LIBRARY Connecticut Agricultural Gqllec VOL. ..t3..aL5i.b.. .,*^ CLAS >Sk Oct. .^(1 BOOK 615.14.R83 1 c 1 3 T1S3 0003bmi ^ ''i';'-* "*" ' ' ■ ■ V.'-'-'-" '. K - ' y^^:^i This Book may be kept out TIT^O IVEEKS INCOMPATIBILITIES IN PRESCRIPTIONS. STUDENTS IN PHARMACY AND MEDICINE AND PRACTICING PHARMACISTS AND PHYSICIANS. BY EDSEL A. RUDDIMAN, Ph.M., M.D., Professor of Pharmacy and Materia Medica in Vanderbilt University. SECOND EDITION, REWRITTEN. FIRST THOUSAND. NEW YORK: JOHN WILEY & SONS. London : CHAPMAN & HALL, Limited. 1900. Copyright, 1897, 1900, BY E. A. R U D D I M A N . Q8 3 b, ROBERT DRUWMOND, EUECTaOTYPER AND PRINTER. NEW YORK. PREFACE TO THE SECOND EDITION. In this edition Part I has been entirely rewritten. Many of the statements made in the first edition have been gone over in the Author's laboratory; a few were found to be in- correct, while a modification of others was necessary. In performing the laboratory work the fact was again empha- sized that many conditions, such as temperature, dilution, order of mixing, impurities in commercial drugs, etc., materi- ally affect the results obtained. The text of this part of the book has been made rather full so that as a reference book it may have some value. At the same time the insertion of numbers at the beginning of the statements makes it easy for the teacher using the book to designate what incompatibili- ties he wishes the student to learn. Some changes and additional statements have been made in Part II. Twenty-five prescriptions with comments have also been added as well as fifty prescriptions without com- ments. The comments on the last were omitted so that the student can the better test his knowledge. Since so many incompatibilities are the result of the formation of insoluble compounds it was deemed advisable to introduce a table of solubilities for reference. A table of average prices charged for prescriptions not requiring par- ticular skill or calling for expensive ingredients is also. ap- pended, so that those who have not had the drug-store experi- ence may have some idea as to the general prices charged. Attention is called to the complete index of prescriptions IV PREFACE. which enables one to find at a glance any prescription con- taining a certain ingredieiit or combination of ingredients that is given in the book. The Author has found this book to be of as much value to medical students as to those in Pharmacy. Since the in- compatibility in a prescription originates with the physician, if the subject were better understood by the writer of the prescription there would be less trouble both for physicians and pharmacists. The Author wishes to thank his many friends for the gen- erous words of encouragement that they have given him. Vanderbilt University, June, 1900. PREFACE TO THE FIRST EDITION. The busy prescriptionist is frequently at a loss to know what takes place in the prescription he is filling, and does not have the time nor books necessary to look up the change which he has noticed. The object of the first part of this book is to present to him in a convenient and condensed form the more common incompatibilities. The substances treated of are arranged in alphabetical order of their Latin names, except in case of some of the newer remedies. In order to avoid repetition all the incompatibilities of each substance are not always given under that heading. For instance, the reaction between two substances may be found under the heading of one of the substances and not under the other. The second object of the writer is to furnish the student of pharmacy with a list of incompatible prescriptions in such form that he may find out for himself what the trouble is, and the best means of avoiding or overcoming it. It is suggested that he study the prescription thoroughly before referring to the notes. Acknowledgment is hereby made of assistance received from all of the books and journals mentioned in the list of abbreviations of references. Edsel a. Ruddiman. Nashville, June, 1S97. V ABBREVIATIONS OF REFERENCES. Allen : Allen's Commercial Organic Analysis, 2d ed. A. D. : American Dispensatory. Am. D. : American Druggist. A. J. A. : American Journal of Pharmacy. A. P. A. : Proceedings of the American Pharmaceutical Association. BIyth : Blyth's Poisons, 3d ed. Br. P. : British Pharmacopoeia, 1898. Caspari : Caspari's Treatise on Pharmacy. Coblentz : Coblentz's New Remedies, 2d ed. D. C. : Druggists' Circular. Extra Pharm.: The Extra Pharmacopoeia, by Martindale and Westcott, 7th ed. M. & M. : Muir and Morley's edition of Watts' Dictionary. M. M. R. : Merck's Market Report. Nat. Drug.: National Druggist. N. D. : National Dispensatory, 5th ed. N. E. D. : New England Druggist. Ph. E. : Pharmaceutical Era. P. D. : Thompson's Practical Dispensing. P. & J. : , Prescott and Johnson's Qualitative Chemical Analysis,. 4th ed. Potter : Potter's Materia Medica, 6th ed. Prescott : Prescott's Organic Analysis. R. & S. : Roscoe and Schorlemmer's Organic Chemistry. - Richter: Richter's Organic Chemistry. Sayre : Sayre's Organic Materia Medica. Scoville : Scoville's Art of Dispensing. Sohn : Sohn's Dictionary of Active Principles of Plants. Squire : Squire's Companion to the British Pharmacopoeia, l6th ed» Storer : Storer's Dictionary of Solubilities. U. S. D. : United States Dispensatory, 17th ed. U. S. P. : United States Pharmacopoeia, 7th revision. W. D. : Western Druggist. Wade : Wade's Organic Chemistry, 1897. Watts : Watts' Dictionary of Chemistry. vi PART I. INCOMPATIBILITIES. Acacia. — i. Mucilage of acacia is acid to litmus paper but is not sufficiently acid to cause trouble unless decompo- sition has commenced. 2. The official mucilage of acacia is gelatinized by a solution of ferric chloride, tincture of ferric chloride, solution of ferric sulphate, solution of ferric sub- sulphate, or solution of iron and ammonium acetate. Alkali citrates tend to prevent this coagulation and, in the proportion of about one grain of the citrate to two drams of the tincture of iron, will entirely prevent it. Potassium or ammonium acetate in considerable proportion will prevent coagulation, as will also a rather large excess of hydrochloric acid or other mineral acids. Dilution with water will prevent coagulation ; one volume of tincture of iron with an equal volume of water will give a solution with one volume of mucilage of acacia diluted with an equal amount of water. Glycerin or syrup seems to have but little more effect in preventing coagulation than so much water. The color of the mixture of the iron salt and the mucilage is much deeper red than that of the tincture alone. Gelatinized acacia will after- wards slowly dissolve if an excess of water is added. 3. So- lution of dialyzed iron when mixed with mucilage of acacia forms gelatinous masses, having the color of ferric hydrate, but does not give a translucent mass as does the tincture of iron ; dilution with water or the addition of a citrate has but little effect in preventing precipitation. 4. The solution of 2 INCOMPATIBILITIES IN PRESCRIPTIONS. ferrous chloride (N. F.) or a saturated solution of ferrous sulphate does not gelatinize mucilage of acacia. 5. A saturated solution of borax forms a more or less translucent mass with mucilage of acacia. By diluting the borax solu- tion with an equal volume of water and the mucilage with an equal volume of water, no coagulation takes place. The coagulation may also be prevented by adding three or four drops of glycerin or honey to one dram of the borax solution. Either glycerin or honey decomposes borax to some extent, liberating boric acid, but not enough need be added to make the solution acid. The official syrup or a solution of glucose tends to prevent the c®agulation but is not as effective as glycerin. 6. A solution of lead subacetate (not the neutral lead acetate), even if quite highly diluted, will give white, opaque, gelatinous masses when mixed with mucilage of acacia. Diluting the mucilage with several volumes of water does not prevent coagulation although glycerin and syrup do to some extent. 7. A solution of an oxalate or a carbonate when mixed with mucilage of acacia will give a white precipi- tate of calcium oxalate or calcium carbonate. 8. A saturated solution of mercuric chloride with an equal volume of muci- lage of acacia slowly gives a white precipitate. 9. Acacia is nearly insoluble in alcohol, consequently when alcohol or a preparation containing strong alcohol is added to mucilage of acacia in sufficie«,t amount to make the mixture about fifty or sixty per cent, of alcohol, the acacia is precipitated. The precipitate redissolves on subsequent dilution with water. 10. Sulphuric acid converts acacia into arable and then metarabic acid and precipitates calcium sulphate (U. S. D., 8). Dilute sulphuric acid converts it into a sugar (M. &M.,I. 296). A strong solution of a sulphate gives a precipitate of calcium sulphate. 11. Dilute nitric acid converts acacia into mucic, saccharic, oxalic, and tartaric acids (U. S. D., 8). 12. In the presence of acacia, dilute solutions of salts of mercury, lead, copper, antimony, silver, iron, or arsenic do not give precipitates with hydrogen sulphide or alkaline sulphides, INCOMPATIBILITIES IN PRESCRIPTIONS. 3 although a coloration may be produced. 13. Acacia pre- vents the precipitation of dilute solutions of salts of mercury, antimony, aluminum, iron, calcium, and some other metals by alkali hydrates or borax and in some cases by carbon- ates. 14. Dilute solutions of alkaloidal salts in the pres- ence of acacia are not precipitated by potassium mercuric iodide, sodium phosphomolybdate, or tannic acid (Allen, i, 353). These properties are common to many gums (M. & M., I. 296). The solution of the alkaloid must be very dilute or some precipitation will occur. 15. Mucilage of acacia is colored blue, either at once or after standing a short time, by a tincture of guaiac if the guaiac is fresh ; but with an old guaiac the color is red brown. Aceta. [See under AciDUM ACETICUM.] Acetamid. — i. Acetamid acts both as an acid and as a base, combining with bases or acids (Watts, i. 5). With acids it forms unstable compounds (Richter, 259). 2. Boiled with acids or alkaliest is decomposed, forming acetic acid and ammonia (Richter, 259). 3. Acetamid gives a liquid or soft mass when triturated with antipyrin, bromal hydrate, butyl chloral hydrate, carbolic acid, chloral alcoholate, chloral hydrate, lead acetate, pyrocatechin, pyrogallol, resorcin, sodium phosphate, thymol, or urethane. 4. With chloral it unites directly, forming chloral acetamid (M. & M., I. 5). Acetaiiilidum. — i. With spirit of nitrous ether, amyl nitrite, or a solution containing nitrous acid, acetanilid gives a yellow solution, becoming red on standing for some time. With a fresh or nearly neutral spirit of nitrous ether the yellow coloration may not be noticed for several days and the red for two weeks or more. The presence of an alkali or a little sodium bicarbonate will prevent the appearance of more than a pale yellow within a month. Probably diazo- compounds are formed. 2. A cold solution of ferric chlo- ride with acetanilid gives no increase of color, but, if heated, it assumes a deep red color which fades as the solution cools. 4 INCOMPATIBILITIES IN PRESCRIPTIONS. If heat is applied to a concentrated solution for several min- utes a dark green color is produced. With the tincture of iron acetanilid gives a red color without heating, 3. On adding an aqueous solution of bromine to a saturated solu- tion of acetanilid, the color of the bromine is destroyed and a precipitate is formed which at first redissolves but remains permanent on adding more bromine. The precipitate is white, crystalline, and soluble in alcohol. 4. A solution of iodine does not readily precipitate an aqueous solution of acetanilid. 5. The alkali bromides or iodides in aqueous solution with acetanilid form insoluble compounds (Coblentz, i). This statement is only partly true. If thirty grains of potassium bromide are added to a fluid dram of a saturated solution of acetanilid, a fine white precipitate is formed at once. This may be due to the acetanilid being less soKible in a solution of a bromide than it is in water. If the thirty grains of bromide are dissolved in one dram of water and then added, no precipitation takes place in a week. If thirty grains of potassium iodide are added to one dram of a saturated solution of acetanilid, no precipitation occurs. 6. Acetanilid is slowly decomposed by a strong solution cf potassium or sodium hydrate, forming anilin (U. S. D., 10). 7. A dry mixture of acetanilid and calomel shows no percep- tible change within a month. On allowing a mixture of these with water to stand for six weeks, there was no change in the color of the calomel and the filtrate gave no test for a mercuric salt. After heating a mixture of acetanilid and calomel in water acidulated with hydrochloric acid and allow- ing to stand for six weeks, the filtrate gave a test for a mercuric salt. 8. When acetanilid is rubbed with chloral hydrate, a sticky mass is said to be produced (M. M. R., iv.. 359), but the writer only got a slightly damp powder after hard trituration. Chloral hydrate increases the solubility of acetanilid in water; a mixture of ten grains of chloral hydrate with one grain of acetanilid will dissolve in about five minims of water and furth&r addition of water does not cause pre- INCOMPATIBILITIES IN PRESCRIPTIONS. 5 cipitation. 9. Rubbing acetanilid with resorcin gives a soft mass which liquefies on standing. Water seems to dissolve the resorcin but not the acetanilid. The mass is soluble in alcohol. 10. Acetanilid triturated with thymol gives a soft mass which is soluble in alcohol but not in water. Gently mixing the two without rubbing produces a mass which soon liquefies. ii. When acetanilid is triturated with chloral alcoholate, carbolic acid, or pyrocatechin a mass or liquid results which is soluble in alcohol but insoluble or only partly soluble in water. 12. Triturating acetanilid with antipyrin ordinarily produces a dry powder, but by rubbing hard a damp powder can be obtained. Alcohol dissolves the mixture, but water seems to dissolve only the antipyrin. 13. When sodium salicylate is mixed with acetanilid a pink powder is said to be produced, but the writer did not get much increase of color, although the paper containing the mixture became colored after a time. 14. Acetanilid is readily soluble in a hot solution of tartaric acid from which it does not recrystallize on cooling (P. D., 19). However, a hot solution of three grains of acetanilid and fifteen grains of tartaric acid in three drams of water gave an abundant pre- cipitate of crystals on cooling. 15. Strychnine and atro- pine are somewhat antagonistic physiologically to acetanilid. Acetates. [See under AciDUM Aceticum.] Acida. — I. Acids combine with metallic oxides and hydrates, with some metals, and with some alkaloids to form salts. 2. Mineral acids and some organic acids, such as tartaric or acetic, precipitate bismuth citrate from solutions of bismuth and ammonium citrate by combining with the ammonium. 3. Mineral and common organic acids precipi- tate potassium bitartrate from concentrated solutions of Rochelle salt, normal potassium tartrate, or double tar- trates containing potassium. 4. Nitric, hydrochloric, or sul- phuric acid with an aqueous solution of tartra emetic gives a precipitate consisting of a basic nitrate, chloride, or sul- phate of antimony. 5. Mineral acids give a precipitated 6 INCOMPATIBILITIES IN PRESCRIPTIONS. the phosphate or the pyrophosphate of iron when added to a solution of the official soluble phosphate or pyrophosphate of iron. 6, Strong mineral acids precipitate, from concen- trated solutions of borates, salicylates, or benzoates, the boric, salicylic, or benzoic acid. 7. Strong mineral acids form esters and ethers with alcohol. Many organic acids in the presence of mineral acids, as sulphuric or hydrochloric, form esters with alcohol. 8. Nearly all acids, except hydro- cyanic and hydrosulphuric, decompose carbonates, liberating carbon dioxide. 9. Acids diminish or prevent the action of pancreatin. 10. Many acids precipitate albuminous sub- stances from aqueous solution. ii. Organic acids, except acetic, combined with an alkali, generally form compounds with the heavy metals that are insoluble in water. 12. Frequently mineral acids displace organic acids and the stronger mineral acids the weaker ones. The following official preparations contain a free acid: 13. the vinegars of opium and squills; 14. hydrogen dioxide water; 15. styptic collodion; 16. fluid extracts of conium, ergot, nux vomica, and sanguinaria; 17. fluid extracts in general are acid to litmus, some sufficiently acid to liberate carbon dioxide from carbonates; 18. glycerites of tannic acid and boroglycerin ; 19. solutions of arsenous acid, am- monium acetate, chloride of iron, citrate of iron, iron and ammonium acetate, nitrate of iron, subsulphate of iron, ter- sulphate of iron, and nitrate of mercury ; 20. oleates of mer- cury, veratrine, and zinc; 21. spirit of nitrous ether, usually; 22. syrups of citric acid, hydriodic acid, garlic, calcium lacto- phosphate, hypophosphites, ipecac, iron quinine and strych- nine phosphates, and squills; 23. tinctures of chloride of iron and sanguinaria; 24. ointment of tannic acid and usually ointment of mercuric nitrate. 25. Besides these there are some substances which become acid on exposure, as acetic ether, spirit of nitrous ether, amyl nitrite, oil of bitter •almonds, and chlorine water. 26. There are quite a number of salts that are acid in re- INCOMPATIBILITIES IN PRESCRIPTIONS. 7 action and sufficiently so to give an effervescence with a car- bonate. Some of the more common are : alum, aluminum sulphate, bismuth subnitrate, ferric chloride, ferric citrate, iron and quinine citrate, iron and strychnine citrate, ferrous sulphate, lead acetate, lead nitrate, quinine bisulphate, zinc acetate, and zinc sulphate. Acidiim Aceticviiii. — i . Acetic acid decomposes nearly all carbonates, liberating carbon dioxide and forming ace- tates. 2. It forms chloracetic acid with chlorine, slowly in diffused light, more quickly in sunlight. 3. Soluble neutral acetates, or the free acid if it is concentrated and the solution of iron salt is weak, with solutions of ferric salts, give a deep red coloration. The color varies from a yellow red to a dark red, according to the dilution, due to the formation of ferric acetate, which on heating precipitates as the basic ferric acetate. The strong mineral acids in excess prevent the formation of the color. 4. Acetic acid aids the solution of quinine sulphate in water, increasing the fluorescence. This solution does not precipitate on standing, but on adding potassium acetate the fluorescence is destroyed and, if it is a fairly strong solution of quinine, needle-shaped crystals will be formed in a few minutes. Experiments made indicate that double decomposition takes place, forming quinine acetate and potassium sulphate. The precipitation may be due partly to the quinine acetate being only sparingly soluble and partly to the quinine salt being less soluble in a solution of potassium acetate. The precipitate formed may be dissolved by the further addition of acetic acid and again thrown down by adding potassium acetate, the amount of potassium acetate necessary seeming to depend on the excess of acetic acid used. It may be that the potassium acetate combines with the acetic acid (as explained in R. & S., III. part I. 497), forming potassium diacetate, thus taking up the free acid. Potassium acetate in sufficient amount will destroy the fluorescence and give a precipitate with a solution of quinine bisulphate or quinine sulphate dissolved in water by the aid of sulphuric acid. It has been suggested that S INCOMPATIBILITIES IN PRESCRIPTIONS. •quinine hydrate is formed, the acetic acid being too weak to hold the hydrate in solution (M. M. R., IX. 158). 5. A mixture of alcohol, sulphuric acid, and acetic acid or an ace- tate gives ethyl acetate, which has a fruity odor. 6. An aqueous solution of potassium acetate with spirit of nitrous ether produces an effervescence. Nitrous acid converts ace- tates into carbon monoxide and other gases (Scoville, 223). [See comment on prescription No. 350.] 7. The stronger mineral acids transpose acetates, liberating acetic acid. 8. Acetic acid is not sensibly affected by nitric acid or readily changed by oxidizing agents. 9. Strong acetic acid is a good solvent for resins, gum-resins, camphor, and volatile oils. 10. Some acetates, as lead, on being exposed to the air lose acetic acid and absorb carbon dioxide, becoming partly insoluble. ii. Nearly all normal acetates are readily soluble in water, except quinine, silver, and mercurous. The ace- tates, except silver and mercurous, are generally soluble in alcohol. [See AciDA.] Aciduiii Arsenicum. — i. The normal alkali arsenates, as sodium arsenate, precipitate neutral solutions of salts of nearly all other common metals, as arsenates. Sodium arsenate is sometimes alkaline, and may cause precipitation on this account. The precipitate is soluble in mineral acids and sometimes in the presence of ammonium salts. 2. Tan- nic acid with a not too dilute solution of sodium arsenate gives a yellow-brown precipitate, the precipitate . and the liquid changing to a dark green within a day or two. 3. In acid solutions arsenates are reduced to arsenites by hypophos- phites, sulphites, and iodides, forming respectively phos- phoric acid, sulphuric acid, and iodine. 4. Sodium arsenate precipitates solutions of many alkaloidal salts, due perhaps to the fact that the arsenate is frequently alkaline and in some cases to the formation of an insoluble alkaloidal arse- nate. 5. The arsenates of the alkali metals are soluble in water. The di- and tri-metallic salts of the other metals are insoluble in water, but soluble in the presence of most min- INCOMPATIBILITIES IN PRESCRIPTIONS. g €ral acids. The arsenates are generally insoluble in alco- hol. Acidvini Arsenosum. — i. Arsenous acid combines with alkali hydrates and carbonates to form arsenites. 2. The soluble arsenites (generally not the free acid) pre- cipitate neutral solutions of nearly all metallic salts, except those of the alkalies. 3. Ferric hydrate or a solution of dialyzed iron gives an insoluble basic arsenite with a solution of an arsenite or arsenous acid. To some extent this is changed to a basic ferrous arsenate (P. & J., 118). 4. Arse- nous acid is said to combine with potassium acid tartrate to form a double salt, analogous to tartar emetic (Watts, V. 686). 5. A solution ef potassium iodide with arsenous acid or potassium arsenite yields a precipitate of (KI)2(As203) which is sparingly soluble in water (Watts, I. 373). One dram of potassium iodide dissolved in one dram of Fowler's solution gives only a slight precipitate. 6. Fowler's solution gives a brown-white precipitate with lime water. 7. With tannic acid, it gives a nearly white precipitate which with the liquid turns to a dark, dirty green in less than a day. 8. With a solution of mercuric chloride Fowler's solution gives a white precipitate, consisting of a mercurous salt. If the Fowler's solution is in large excess there will be formed a white precipitate at first and in a few hours a dark gray precipitate of metallic mercury. 9. Fowler's solution is alkaline and may precipitate solutions of alkaloidal salts and other neutral salts. 10. Arsenous compounds are oxidized to arsenic compounds by nitric acid, chlorine, chlorates in acid solution, iodine in alkaline solution, silver salts in alkaline mixtures, mercuric or mercurous compounds in alkaline mixtures, ferric compounds in alkaline mixtures, permanga- nates, or chromates. 1 1. Arsenous compounds are reduced to metallic arsenic by hypophosphites in acid mixtures. 12. Arsenites of potassium, sodium, or ammonium are solu- ble in water; barium and strontium are sparingly soluble; the other metallic arsenites are insoluble. They are generally 10 INCOMPATIBILITIES IN PRESCRIPTIONS. dissolved and decomposed by dilute mineral acids. [See AciDA.] Acicluiii Beiizoicvim. — i. Benzoic acid combines with the hydrates of the alkalies and calcium to form benzoates. 2. It liberates carbon dioxide from carbonates. 3. Soluble benzoates precipitate nearly neutral solutions of ferric salts as ferric benzoate, which is flesh colored. The presence of an excess of free acid or of alkali tartrates interferes with or prevents the precipitation. 4. Sodium benzoate gives precip- itates with solutions of salts of silver, mercury, and lead, the latter being somewhat soluble in excess of lead acetate. 5. Sodium benzoate gives a white, sticky precipitate when it is added to a solution of quinine bisulphate or to a slightly acidulated solution of quinine sulphate if the quinine solution is not too dilute. Quinine benzoate is soluble in about 370 parts of water and more soluble in alcohol. 6. Hydrogen dioxide with a little sulphuric acid converts benzoic acid into salicylic acid (M, & M., I. 470). 7. Benzoic acid is not readily attacked by nitric or chromic acid. 8. Concentrated aqueous solutions of benzoates give a crystalline precipitate of benzoic acid when dilute solutions of strong acids are added. 9. Most benzoates are soluble in water and many are soluble in alcohol. The more sparingly soluble benzoates dissolve readily in aqueous solutions of sodium acetate, lead acetate, or sodium nitrate (Storer, 61). 10. The solubility of the free acid in water is increased by the presence of borax, alkali citrates, or sodium phosphate. 11. Benzoic acid dis- solves in a concentrated solution of sodium sulphite, forming sodium benzene-sulphinate which is very soluble (Allen, III. part I. 12). [See AciDA.] Acidum Boricum. — i. Boric acid combines with the hydrates of the alkalies and the alkaline earths to form borates. 2. It decomposes carbonates of the alkalies and of the alkaline earths, liberating carbon dioxide, but under certain conditions carbon dioxide may decompose borates. 3. The alkali borates, as borax, give precipitates with nearly INCOMPATIBILITIES IN PRESCRIPTIONS. n neutral solutions of salts of several metals, the precipitate being more or less soluble in excess of the metallic salt or in the presence of ammonium chloride (Watts, i. 641); 4. with mercuric chloride the precipitate is the red-brown basic mercuric chloride (Watts, I. 641); 5. with silver nitrate the precipitate is silver borate (sometimes mixed with a little oxide) ; 6. with lead acetate, barium chloride, or calcium chloride the precipitate is a borate of the metal (P. & J. , 164) ; 7. with alum the precipitate is aluminum hydroxide; 8. with zinc sulphate the precipitate may be chiefly a borate or a mixture of the borate with a basic compound (Watts, I. 649); 9. with ferric salts a basic borate is formed (Watts, I. 530). 10. The alkali borates are alkaline in reaction, consequently cause a precipitation with most alkaloidal salts, liberating the alkaloid. 11. Concentrated solutions of borates give a precipitate of boric acid with nearly all mineral acids. 12. All of the borates, excepting the alkali borates, are nearly insoluble in water but are generally soluble in the presence of free boric, tartaric, and mineral acids. They are all nearly insoluble in alcohol. 13. The solubility of the free acid is increased by the presence of tartaric acid, potas- sium tartrate, or Rochelle salt, the salts being partially decomposed (Watts, l. 639). Boric acid seems to act the part of a base with tartaric acid (Watts, I. 648). [See AciDA and SODII BORAS.] Acidviiu Carbolicum. — i. Carbolic acid exposed to the air absorbs enough of moisture to liquefy it. 2. On exposure to air and light it becomes pink, red, and even brown. This is probably due to several causes, no explana- tion being entirely satisfactory. 3. Carbolic acid with ammonia water gives a colorless solution which slowly becomes green, then deep blue, and finally purplish blue. 4. With ammonia water and a solution of chlorinated soda it gives a deep blue. 5. Carbolic acid combines with con- centrated solutions of fixed alkali hydrates to form car- bolates. It does not combine with alkali carbonates, except 12 INCOMPATIBILITIES IN PRESCRIPTIONS. perhaps on boiling. 6. Alkaline solutions of carbolic acid absorb atmospheric oxygen, forming dark-colored products. 7. Carbolic acid with the U. S. P. solution of ferric chloride gives no change in color but on adding water a green is pro- duced and on further dilution gives a violet-blue color. This violet-blue color is prevented or destroyed by most mineral and organic acids, by some salts, and by many organic substances such as alcohol, ether, and glycerin. 8. Gelatin is completely dissolved by strong carbolic acid but is coagulated when the acid is added in excess to its aqueous solution (Allen, II. 539). 9. Carbolic acid coagulates aqueous solutions of albumin. 10. It coagulates collodion (difference from creosote), separating the nitro-cellulose as a gelatinous mass. 1 1. Hydrogen dioxide oxidizes it to pyro- catechin, quinone, and hydroquinone (M. & M., III. 832). The solution becomes yellow to red brown on standing. 12. Potassium permanganate oxidizes it to oxalic acid and carbon dioxide (N. D., 39). 13. Nitric acid oxidizes it to mono-, di-, and tri-nitrophenol, the latter being picric acid. 14. Nitrous acid forms nitroso-phenol. Spirit of nitrous ether with carbolic acid gives a yellow color, changing to a red brown in a few minutes, then to a deep brown-red; after some hours a precipitate forms. 15. Carbolic acid with strong sulphuric acid forms phenol- sulphonic acid. 16. Phenol is scarcely, if at all, attacked by iodine (Watts, IV. 390). 17. An aqueous solution of phenol with bromine water gives a crystalline precipitate of tribromo-phenol which is not so very soluble in dilute alcohol. 18. Carbolic acid reduces salts of several of the metals, as silver, copper, and mercury. 19. On mixing aqueous solutions of carbolic acid and antipyrin an oily liquid settles to the bottom. 20. Crystalline carbolic acid gives a soft mass or a liquid when triturated with acetamid, ace- tanilid, antipyrin, borneol, bromal hydrate, butyl chloral hydrate, camphor, monobromated camphor, chloral alco- holate, chloral hydrate, chloralamid, diuretin, euphorin^ INCOMPATIBILITIES IN PRESCRIPTIONS. 13 exalgin, lead acetate, menthol, methacetin, naphtaiin, naphtol, phenacetin, pyrocatechin, pyrogallol, resin, resor- cin, salol, sodium phosphate, terpin hydrate, thymol, or urethane. These reactions are due in some cases to the for- mation of new chemical compounds, and in some cases proba- bly to the fact that carbolic acid is hygroscopic, and also that it liquefies when warmed by trituration. 21. Atropine, hy- podermatically, is a very complete physiological antagonist, maintaining the heart and respiration (Potter, yy). Recent experiments indicate that alcohol is in some way antagonistic to carbolic acid. Aciduiii Chromicuni — i. Chromic acid combines with the alkali hydrates to form yellow normal chromates and red dichromates. 2. Chromic acid, or chromates in solution with sulphuric acid, are reduced to chromic salts by tartrates, producing formic acid, carbon dioxide, and water; 3. by oxalates, forming carbon dioxide; 4. by hypophos- phites (no action in alkaline mixtures), forming phosphoric acid; 5. by sulphides, liberating sulphur; 6. by sulphites, forming sulphuric acid ; 7. by chlorides, liberating chlorine; 8. by bromides, liberating bromine; 9. by iodides, liberat- ing iodine; 10. by dilute alcohol, forming aldehyde and acetic acid. ii. Chromic acid, with strong alcohol, glyce- rin, ether, volatile oils, or other readily oxidizable matter, is liable to cause an explosion or fire, 12. The soluble chro- mates and bichromates precipitate aqueous solutions of salts of lead, silver, mercury, bismuth, manganese, barium, and strontium as chromates, generally normal, varying in color from yellow to red. 13. Potassium bichromate precipitates many alkaloids from aqueous solutions of their salts, e.g., atropine, codeine, hydrastine, quinine, strychnine, morphine (only in concentrated solutions, i : 100). The normal potas- sium chromate does not precipitate as many of the alkaloids as the bichromate, 14, Bichromates are liable to cause an explosion when triturated with tannic acid, sugar, or other substances that are easily oxidized. 15. The chromates of 14 INCOMPATIBILITIES IN PRESCRIPTIONS. the alkalies, magnesium, calcium, and zinc are soluble in water; the others are sparingly soluble. They are nearly insoluble in alcohol, Acidum Clirysoplianicum. — i. Chrysophanic acid is dissolved by aqueous solutions of alkalies, forming a liquid which is pink when dilute and dark purplish-red when concen- trated. This solution, when neutralized with acids, precipi- tates the yellow chrysophanic acid (Allen, ill. part I. 282). 2. An ammoniacal solution of chrysophanic acid gives a lilac- colored precipitate with acetate of lead and rose-colored with alum (Allen, III. part I. 283). Acidum Citricum. — i. Citric acid forms citrates with most metallic hydrates or carbonates, with most acetates, with alkaline sulphides, and with soap. 2. With a strong solution of potassium tartrate or Rochelle salt citric acid forms sodium citrate and potassium bitartrate which is pre- cipitated. 3. A strong solution of citric acid gives a precipi- tate with a solution of bismuth and ammonium citrate, but it may take several hours. 4. Soluble citrates and citric acid when heated with lime water give a precipitate of calcium citrate. 5. Neutral soluble citrates precipitate solutions of lead acetate and silver nitrate as citrates, both being soluble in excess of the precipitant. 6. The normal magnesium citrate is sometimes precipitated in the official solution of magnesium citrate when the citric acid is not present in con- siderable excess. 7. An alkaline solution of a citrate with chlorine gives some chloroform (M. & M., 11. 194). 8. Citric acid is oxidized to acetic and oxalic acids by concen- trated nitric acid (P. & J., 178); it is scarcely attacked by dilute nitric acid (Watts, I. 996). 9. An acidulated solution of potassium permanganate oxidizes it to carbon dioxide and acetone (Allen, I. 453). The free acid is scarcely if at all affected by the permanganate (Prescott, 88). 10. Neutral or nearly neutral solutions of salts of aluminum, iron, nickel, manganese, antimony, mercuric mercury, copper, zinc, chromium, calcium, or magnesium, in the presence of the INCOMPATIBILITIES IN PRESCRIPTIONS. 15 alkali citrates, are not generally precipitated by the alkali hydrates, carbonates, phosphates, or by borax. The ci- trates also sometimes prevent precipitation of the metals by oxalates and sulphates. In many instances there are double compounds formed. If heat be applied precipitation may take place. 11. The insoluble citrates are transposed by the dilute mineral acids. 12. When a drug containing tannin is added to a mixture of a ferric salt and an alkali citrate, there is a darkening, but the citrate tends to prevent the formation of the black tannate of iron. 13. Citric acid aids the solution of quinine sulphate in water and the solution is fluorescent. If an alkali citrate is now added to this the fluo- rescence is destroyed and in a few minutes a crystalline pre- cipitate forms. This may be dissolved by the further addi- tion of citric acid or a mineral acid. Quinine citrate is soluble in 806 parts of water (N. D., 1326). 14. The presence of an alkali citrate increases the solubility in water of some acids as gallic, salicylic, and benzoic. 15. The citrates of the alka- lies are soluble in water; those of iron, zinc, and copper are moderately soluble; the other single citrates are nearly insol- uble. Citric acid in excess converts the insoluble citrates into the more soluble acid citrates, and the alkali citrates convert them into the more soluble double citrates. [See AciDA.] Aciduin Gallicuni. — i. An aqueous solution of gallic acid soon decomposes when exposed to air, giving off carbon dioxide, turning yellow, brown, and black, and depositing a black substance ; this coloration is hastened by alkali hydrates, forming tanno-melanic acid (Allen, III. part I. 68). 2. Gallic acid combines with alkali hydrates. In mixtures of the acid and a solution of potassium or sodium hydrate, when the acid is in excess, the color becomes green ; when the alkali is in excess, the color is yellow, changing to red and brown. 3. Gallic acid in excess with ammonia water gives a yellow color, but when the ammonia is in excess the color is red brown. 4. It decomposes alkali carbonates, liberating car- bon dioxide and producing colorations similar to those given l6 INCOMPATIBILITIES IN PRESCRIPTIONS. when added to fixed alkali hydrates. 5. With an excess of sodium bicarbonate a solution of gallic acid turns brown, then green and ultimately blue, and gives a precipitate of a deep blue-green solid (Allen, III. part I. 68). 6. Gallic acid with lime water in excess gives a blue-white precipitate, and the liquid acquires a tint which is blue by reflected and green by transmitted light, and becomes pink with a large excess of lime water. If the acid is in excess the color is brown. 7. Gallic acid gives a blue-black solution or precipitate with a solution of ferric chloride. With an excess of the iron the color is green blue to a green brown. Heat changes the blue- black color to brown, due (according to Allen, in. part I. 68) to the reduction of the ferric iron to the ferrous condition, or (according to the U. S. D., 50) to the conversion of gallic acid into pyrogallic or metagallic acid. 8. Gallic acid with a strong solution of a pure ferrous salt gives a white precipi- tate. On exposure to air the mixture soon becomes colored, due to the oxidation of the iron. 9. With a solution of potassium cyanide gallic acid gives a transient red color. 10. With a solution of tartar emetic it gives a precipitate of gal- late of antimony ; in dilute solution the precipitation is pre- vented by ammonium chloride, ii. Gallic acid produces a precipitate when added to a solution of lead acetate. 12. It reduces salts of silver and gold to the metals. 13. Oxidizing agents, such as arsenic acid, silver nitrate, or iodine, with water, convert gallic acid into elagic acid (Richter, 783). 14. Triturating gallic acid with potassium permanganate may cause the acid to take fire. 15. With spirit of nitrous ether gallic acid or a solution of gallic acid produces an effervescence and gives a red color. 16. Gallic acid does not precipitate solutions of alkaloids, gelatin, albumin, or starch, but a mix- ture of gum acacia and gelatin is precipitated (Allen, iii. part I. 68). 17. The solubility in water of the free acid is increased by borax or alkali citrates. 18. The gallates of the alkalies are soluble, but the others are nearly insoluble in water and generally insoluble in alcohol. INCOMPATIBILITIES IN PRESCRIPTIONS. ly Acidum Hydriodicum. — i. Hydriodic acid and am- -monium iodide on being exposed to air and light liberate iodine. 2. An alkali iodide in aqueous solution with mineral acids, certain organic acids as citric or tartaric, or some neu- tral salts as ammonium nitrate is quite easily decomposed, liberating iodine. In some cases an intermediate product is hydriodic acid, which is oxidized by the air. 3. Hydriodic acid and soluble iodides precipitate solutions of salts of lead, as the bright yellow lead iodide. This is prevented to some extent by alkali acetates. 4. They precipitate salts of silver, as the yellow-white silver iodide ; of mercurous mercury, as the yellow mercurous iodide ; of mercuric mercury, as the red mercuric iodide. 5. The alkali iodides in excess form double compounds with lead, silver, and mercuric iodides, which compounds are soluble. The solution of the double salt of mercuric and potassium iodide (KI)5HgI, is known as "Mayer's reagent," and precipitates nearly all alkaloids from their aqueous solutions. 6. Mercurous iodide with an ex- cess of potassium iodide in the presence of water is decom- posed, forming metallic mercury and mercuric iodide, the lat- ter combining with potassium iodide to form the potassium mercuric iodide. 7. Calomel with water and an excess of potas- sium iodide forms mercurous iodide and potassium chloride; the mercurous iodide is decomposed as given under No. 6. 8. Soluble iodides reduce cupric salts in solution and give a white precipitate of cuprous iodide ; at the same time the solution turns red, due to the liberation of iodine. 9. Soluble iodides with ferric salts in acid solutions reduce the ferric to ferrous iron, but give no precipitate of iron ; iodine is liberated and if all of the iodide is decomposed may be precipitated. 10. When bismuth subnitrate is added to syrup of hydriodic acid it is changed to a yellow substance at once which further changes to orange-red and then to dark gray. Sometimes the ultimate precipitate seems to consist of two different sub- stances, one yellow and the other gray. When bismuth sub- nitrate is added to a solution of potassium iodide it assumes a l8 INCOMPATIBILITIES IN PRESCRIPTIONS. yellow color in a few hours and within a day it has changed to a deep red. The color varies with the iodide formed; BiOI is red; sBiOI, 461,0, is yellow ; Bil^ is dark gray (M. & M., I. 513). II. Spirit of nitrous ether, or nitrites in acid solution, liberate iodine from iodides and give off oxides of nitrogen. 12. Nitric or nitrohydrochloric acid liberates iodine from iodides and, if sufficiently concentrated, oxidizes it to iodic acid. 13. Chlorine oxidizes iodides, forming iodine then iodic acid and in an alkaline mixture a periodate. The chlorine is changed to a chloride. 14. Chlorates in an acid solution of an iodide liberate iodine and then change it to iodic acid. Probably a similar reaction takes place in the stomach when a chlorate and an iodide are taken together. 15. lodates in acid solution with iodides liberate iodine from both. Iodides sometimes contain iodates as impurities, hence the liberation on adding an acid. 16. Arsenic compounds in acid solution with iodides liberate iodine and become ar- senous. 17. A solution of potassium iodide with arsenous acid or potassium arsenite yields a precipitate of 2¥A, T^AsJd^ which is sparingly soluble in cold water (Watts, I. 377). When one dram of potassium iodide is added to one fluid dram of the U. S. P. solution of potassium arsenite, a white percipitate forms in a few hours ; if half that amount of iodide is added the precipitation may not take place for several days. 18. Chromates in acid solution liberate iodine and form chromic salts. 19. Permanganates in acid solutions liberate iodine and, if in great excess, oxidize it to iodic acid. 20. Hydrogen dioxide in acid solution liberates iodine from iodides, slowly in neutral mixtures. 21. The iodides some- times contain carbonates and would then have the incompati- bilities of the carbonates. 22. The alkali iodides precipitate aqueous solutions of many alkaloidal salts. In some cases this is due to the formation of compounds that are less soluble in water than the original salt. When a large excess of the alkali iodide is used it may render the alkaloidal salt less soluble in the solution than it is in water. The precipitation INCOMPATIBILITIES IN PRESCRIPTIONS. 19 in other cases is due to the carbonate occurring as an impurity in the iodide. The presence of alcohol prevents the precipi- tation to a considerable extent. The prescribing of strych- nine sulphate with potassium iodide is particularly dangerous. because the precipitation may not take place for some time. A solution of one twelfth of a grain of strychnine sulphate with five grains of potassium iodide and two drams of water does not usually precipitate at once, but may do so within a few hours. 23. The lead, silver, mercurous, mercuric, cuprous, bismuth, and stannous iodides are nearly insoluble in water; all others are soluble. Nearly all iodides, except lead, silver, and mercurous, are soluble in alcohol. [See AciDA.] Acicluiii Hydrobroinicvini. — i. The soluble bro- mides and hydrobromic acid precipitate solutions of salts of lead, silver, and mercurous mercury as bromides. 2. In concentrated aqueous mixtures alkali bromides form double soluble compounds with lead or silver bromide, which double compounds are broken up by a large amount of water. 3. An aqueous solution of an alkali bromide or of hydrobromic acid causes calomel to turn black and the filtrate gives a test for a mercuric salt. Probably a reaction takes place similar to the one explained under AciDUM Hydriodicum, No. 6. 4. Alkali bromides precipitate strong solutions of mercuric salts as mercuric bromide which is soluble in excess of the mercuric salt or of the alkali bromide. 5. Bromides with nitric acid give bromine. 6. Chlorine forms bromine and hydrochloric acid. In alkaline mixtures a bromate is formed. 7. Chlorates in acid solution give bromine and hydrochloric acid. 8. lodates in acid solution with bromides liberate iodine and bromine. 9. Bromides in acid solutions reduce permanganates to manganous salts and liberate bromine. 10. Chromates in acid solution with bromides form chromic salts and bromine. 11. The alkali bromides precipitate some of the alkaloids from the solutions of their salts similar to the alkali iodides [see AciDUM HYDRIODICUM, No. 22] but are not as apt to do so. The presence of alcohol generally 20 INCOMPATIBILITIES IN PRESCRIPTIONS. prevents this precipitation. 12. The alkali bromides some- times contain carbonates as impurities and would then have the incompatibilities of carbonates and the solution would be alkaline. 13. The metallic bromides are soluble in water, except lead, mercury, silver, copper, and bismuth. They are generally somewhat soluble in alcohol. [See AciDA.] Aciduni Hydrochloricuni. — i. Hydrochloric acid and the soluble chlorides precipitate as chlorides solutions of salts of lead, silver, and mercurous mercury. 2. With a solution of tartar emetic hydrochloric acid gives a precipi- tate of basic chloride of antimony. 3. Hydrochloric acid with chlorates gives chlorine and various chlorides of oxy- gen. 4. Concentrated hydrochloric acid with concentrated nitric acid gives chlorine and oxychlorides of nitrogen. 5. Permanganates liberate chlorine from hydrochloric acid and are reduced to manganous chloride. 6. Chromates form •chromic chloride and free chlorine. 7. Bismuth citrate is precipitated from a solution of bismuth and ammonium ■citrate when hydrochloric acid is added to it. 8. Some writers say that chlorides aid the conversion of calomel to mercuric chloride. [See Hydrargyrum, No. 7.] 9. The soluble chlorides give hydrochloric acid when treated with sulphuric acid. 10. Hydrochloric acid, being stronger than most other acids, except sulphuric and nitric, very frequently ■displaces other acids when they are combined with bases. II. The soluble chlorides when added so as to make a con- centrated solution with a solution of an alkaloidal salt may precipitate the alkaloid. 12. Hydrochloric acid added to an alcoholic solution of myrrh gives a red to a violet color; added to an alcoholic solution of balsam of Tolu gives a yellow color, changing through brown to cherry red ; with many resins a brown color is produced. 13. The normal chlorides, except lead, mercurous, and silver, are soluble in water. Many of the chlorides are soluble in alcohol. [See AciDA.] INCOMPATIBILITIES IN PRESCRIPTIONS. 21 Aciduin Hydrocyaiiicuin Dilutum. — i. The aqueous solution of hydrocyanic acid decomposes into the formate of ammonium (Richter, 266). 2, Potassium cyanide in aqueous solution is decomposed on standing, giving potas- sium formate and ammonia (Watts, li. 218). 3. An aqueous solution of potassium cyanide is quite strongly alkaline, and this alkalinity increases with exposure, due to the absorption of carbon dioxide and the volatilization of the hydrocyanic acid. 4. Concentrated mineral acids produce formic acid and a salt of ammonium (Watts, II. 199). 5. Hydrocyanic acid and the soluble cyanides, except mercuric cyanide, pre- cipitate the white silver cyanide from solutions of silver salts; the precipitate forms soluble double compounds with the alkali cyanides. 6. They decompose mercurous com- pounds, forming metallic mercury and mercuric salts. In case of calomel the powder is turned dark at once on account of the metallic mercury. 7. The alkali cyanides precipitate solutions of lead salts as white lead cyanide. 8. The alkali cyanides precipitate solutions of copper salts as the yellow- green copper cyanide, which is soluble in excess of the alkali cyanide. 9. Potassium cyanide with a solution of ferrous sulphate gives a brown precipitate of ferrous cyanide which dissolves in excess of the alkali cyanide forming potassium ferrocyanide. 10. Nitric acid decomposes cyanides with the evolution of nitrogen and other gases (N. D., 65). 11. With hydrogen dioxide and sulphuric acid cyanides are decom- posed, forming oxamid (U. S. D., 64). 12. Cyanides reduce potassium permanganate and are changed to carbon di- oxide, nitric, nitrous, oxalic, and formic acids (M. & M., II. 346). 13. Chlorine or chlorinated lime with a solution of potassium cyanide forms chloride of cyanogen and hydro- chloric acid (M. & M., 11. 302). 14. With a concentrated solution of iodine potassium cyanide forms potassium iodide and iodide of cyanogen (M. & M., II. 342). Even in dilute solutions the color of iodine is destroyed. 15, Rubbed with potassium nitrate or chlorate, potassium cyanide detonates 22 INCOMPATIBILITIES IN PRESCRIPTIONS. violently. i6. If potassium cyanide and chloral hydrate- are rubbed together reaction takes place with the evolution of a large volume of white fumes. 17. Aqueous solutions of the alkali cyanides being alkaline may precipitate alkaloids from solutions of their salts as the free alkaloids. 18. Cyan- ides of the alkalies and alkaline earths are decomposed by all acids, even carbonic, with the liberation of hydrocyanic acid. 19. The cyanides of the alkalies and the alkaline earths and mercuric cyanide are soluble in water; the others are made soluble in the presence of the alkali cyanides by forming double compounds. Excepting mercuric cyanide they are generally insoluble in alcohol. 20. Atropine and ammonia are physiologically antagonistic to cyanides in that they quicken the heart beat. Acicluin Hypopliosphorosum Dilutum. — i. Di- lute hypophosphorous acid is oxidized to phosphorous and phosphoric acids on exposure to air. 2. Hypophosphorous acid and hypophosphites in acid solution are oxidized to phosphoric acid by nearly all oxidizing agents, and cause a reduction of these agents. 3. Nitrous or nitric acid forms nitric oxide. 4. Sulphurous acid forms sulphur. 5. Chlo- rine and chlorates are changed to hydrochloric acid or chlo- rides. 6. Iodine is reduced to hydriodic acid. 7. Mercu- rous and mercuric compounds are reduced to the metal, even in neutral and alkaline mixtures. Calomel is turned dark at once when mixed with potassium hypophosphite. 8. Permanganates are changed to manganous compounds (to manganese dioxide in alkaline mixtures). 9. Chromates form chromic salts. 10. Cupric sulphate with hypophos- phorous acid gives a precipitate of cuprous hydride which be- gins to form after an hour or more. Copper sulphate with potassium hypophosphite gives a white precipitate. 11. Bismuth subnitrate with a solution of potassium hypophos- phite in the presence of moisture becomes brown in an hour or two. Bismuth is reduced from the condition having a quantivalence of three to that having a quantivalence of twa INCOMPATIBILITIES IN PRESCRIPTIONS. 23 (P. & J., 220). 12. In the presence of hydrochloric acid arsenic acid is reduced to arsenous acid and then to metalHc arsenic (P. & J., 220). 13. Ferric salts are reduced to ferrous (P. & J., 221). When an alkali hypophosphite is added to a solution of ferric chloride a white precipitate of ferric hypophosphite is formed which is dissolved by adding a large excess of hydrochloric acid or an alkali citrate in consid- erable amount. 14. Compounds of silver and gold are re- duced to the metals. 15. Hypophosphorous acid dissolves quinine sulphate with a blue fluorescence. Adding potas- sium hypophosphite to the solution destroys the fluorescence and in sufificient amount precipitates the quinine. 16. Hypo- phosphites are decomposed by nearly all acids. 17. Hypo- phosphites when triturated with some oxidizing agents, as potassium chlorate, are apt to cause an explosion. 18. Hy- pophosphites are soluble in water, except ferric hypophos- phite which is only sparingly soluble. Many are soluble in alcohol. [See Acida.] AcicUmi Lacticum. — i. Lactic acid displaces acetic and carbonic acids from their compounds. 2. It coagulates a solution of albumin. 3. With nitric acid it forms oxalic acid (N. D., 70). 4. With potassium permanganate and sulphuric acid it gives the odor of aldehyde (U. S. P., 16). With potassium permanganate its gives pyruvic acid (M. & M., III. 1 10). 5. Hydriodic acid at once reduces lactic acid to propionic acid (Richter, 357). On mixing lactic acid and syrup of hydriodic acid together no coloration takes place at once, but after some hours the mixture becomes yellow. 6. Lactates are generally insoluble in water and alcohol. [See AciDA.] Aciduin Meconicum. — i. Meconic acid, with a nearly neutral solution of a ferric salt, gives a red-colored solution, the color being destroyed by large excess of hydrochloric acid. 2. With a weak solution of an ammoniated copper sulphate it gives a green precipitate. 3. It gives a white precipitate with solutions of lead acetate, silver nitrate, 24 INCOMPATIBILITIES IN PRESCRIPTIONS. barium chloride, and calcium chloride (U. S. D. 69). 4. Nitric acid converts it into oxalic acid (Allen, ill. part II. 337)- Acidum Nitricum. — i. Nitric acid is a strong oxi- dizing agent, and in oxidizing substances it is reduced to dinitrogen tetroxide (N,0,), nitrous anhydride (N,0,), nitric oxide (NO), nitrous oxide (N,0), nitrogen, or ammonia. 2. Nitric acid oxidizes hypophosphites to phosphates; 3. sulphides to sulphur, and then sulphates; 4. sulphites to sulphates; 5, bromides to free bromine; 6. iodides to free iodine, and then to iodic acid; 7. oxalates to carbon di- oxide; 8. citrates to acetic and oxalic acids; 9. mercurous compounds to mercuric ; 10. arsenous compounds to arse- nic; II. ferrous compounds to ferric. 12. Nitric acid dis- solves many metals, while it itself is partly decomposed. 13. With concentrated hydrochloric acid it forms chlorine and oxychlorides of nitrogen. 14. With carbolic acid it forms picric acid. 15. Nitric acid reacts with tannic acid, giving off oxides of nitrogen. 16. With salicylic acid it forms nitrosalicylic acid. 17. With alcohol it acts violently, giving off red fumes, and forming aldehyde, acetic, formic, and carbonic acids. 18. With creosote, volatile oils, and other organic substances the reaction with nitric acid may be so violent as to cause explosion or ignition. 19. Nitric acid gives color reactions with many of the alkaloids. Apo- morphine with nitric acid gives a violet-red; 20. brucine a scarlet to blood-red; 21. physostigmine, a yellow or red; 22. berberine, a dark brown-red; 23. codeine, a yellow; 24. hydrastine, an orange; 25. morphine, an orange-red, changing to yellow. 26. Nitric acid gives a red color with barbaloin and nataloin, but not with socaloin. 27. Nitric acid replaces many weak acids, such as carbonic, acetic, and boric acids, when they are combined with bases. 28. Nitric acid with concentrated sulphuric acid and glycerin forms the explosive nitroglycerin. 29. With sulphuric acid and cotton or other cellulose it forms gun-cotton, some of the com- INCOMPATIBILITIES IN PRESCRIPTIONS. 25 pounds being explosive. 30. Nitric acid with sugar and heat forms oxalic acid. Very concentrated nitric acid in the cold with sugar forms an explosive compound. Dilute nitric acid oxidizes sugar to saccharic acid, while very dilute acid changes it to glucose. 31. Nitric acid with silver or mer- curic nitrates, and strong alcohol forms the explosive fulmi- nate of silver or mercury. 32. Dilute nitric acid, while an oxidizing agent, is not as active as the concentrated. It may not give color reactions with some of the alkaloids. 33. Fuming nitric acid is a more active oxidizing agent than the concentrated acid. When it is mixed with organic matter, violent explosion or ignition is liable to take place. 34. Nitrates with sulphuric acid give nitric acid. 35. Nitrates, particularly those of the fixed alkalies, when triturated with substances capable of being readily oxidized, are liable to explode; some of these substances are charcoal, phosphorus, sulphur, sugar, sulphides, potassium cyanide, glycerin, alco- hol, and oils. 36. The nitrates are all soluble in water ; the basic nitrates of bismuth and of mercury are insoluble. Most of the nitrates are nearly or quite insoluble in alcohol. [See AciDA.] Acidiini Nitroliydrochloricum. — i. Unless very highly diluted, nitrohydrochloric acid gives a yellow colora- tion with strychnine sulphate. The products formed have not been determined. 2. Nitrohydrochloric acid is a very strong oxidizing agent, and is liable to cause violent reaction when mixed with organic matter. 3. It has the oxidizing properties of chlorine and the precipitating properties of hydrochloric acid. [See Chlorum and AciDUM Hydro- CHLORICUM.] AcicUiin Nitrosvini. — i. Nitrous acid and acid solu- tions of nitrites, such as potassium or sodium nitrite, amyl nitrite or ethyl nitrite (in spirit of nitrous ether), all act in a similar manner. Sometimes they act as oxidizing and some- times as reducing agents. In neutral or alkaline mixtures nitrites do not generally oxidize or reduce. 2. Hypophos- 26 INCOMPATIBILITIES IN PRESCRIPTIONS. phites form phosphoric acid and nitric oxide when mixed with acid solutions of nitrites. 3. Sulphites form sulphates and nitric oxide. 4. Chlorates form peroxide of chlorine, then hydrochloric and nitric acids. 5. Iodides form iodine and nitric oxide. 6. Ammonium bromide is decomposed by- spirit of nitrous ether, liberating bromine. The other bromides are not readily affected. 7. Mercurous salts are re- duced to metallic mercury. 8. Mercuric salts are not re- duced (P. & J., 203). However, the author found that the spirit of nitrous ether after standing with a solution of mer- curic chloride causes the formation of a white precipitate which responds to the tests of calomel. 9. Permanganates are reduced to manganous salts and nitric acid is formed. 10. Chromates are reduced to chromic salts. 11. Gold chloride is reduced to metallic gold. 12. Hydrogen dioxide oxidizes nitrous acid to nitric. 13. Nitrites with sulphuric acid and alcohol form ethyl nitrite. 14. Nitrous acid changes oleic acid to the isomeric form elaidin. 15. Antipyrin with acid solutions of nitrites gives the green isonitroso-antipyrin. [See Antipyrinum ,No. 17.] 16. Aretanilid gives a yellow color with acidulated solutions of nitrites. [See AcETANl- LIDUM, No. I.] 17. Spirit of nitrous ether with sodium salicylate gives a brown-red color if allowed to stand for a day or two. 18. Carbolic acid with spirit of nitrous ether and water gives a yellow solution at once which begins to as- sume a red-brown color in five minutes and in one half hour is a deep red-brown. In a few hours it becomes turbid and de- posits a solid. 19. With tannic or gallic acid or prepara- tions containing them in large amounts, nitrites in acid solu- tion (as an old spirit of nitrous ether) give off gaseous com- pounds, consisting chiefly of oxides of nitrogen. The reac- tion may continue for some time, and bottles containing the mixture should not be stoppered until reaction has ceased. 20. With thymol spirit of nitrous ether gives a green and then a brown color, changing the thymol to nitroso-thymol. 21. Spirit of nitrous ether produces a yellow color with INCOMPATIBILITIES IN PRESCRIPTIONS. 27 morphine. Morphine is converted into nitroso-morphine, pseudomorphine, and another base (M. & M. iii, 436), 22. Spirit of nitrous ether with a tincture of guaiac gives a blue color which changes to deep red in a few minutes. If the guaiac has been exposed to the light and air for some time the blue color is not produced. 23. Nitrous acid con- verts acetates into carbon monoxide and other gases (Sco- ville, 223). An effervescence is frequently quite noticeable. 24. Nitrites are quite soluble in water, except silver which is only sparingly soluble. [See AciDA and Spiritus Aetheris NiTROSI.] Acidiim Oleicum. — i. Oleic acid combines with alka- lies to form soaps. 2. Nitric acid oxidizes oleic acid to acetic, propionic, butyric, valeric, adipic, azelaic, and other acids (M. & M., III. 637). 3. Nitric acid containing nitrous acid fumes or nitrous acid converts oleic acid into the isomeric elaidic acid, which is solid. 4. Potassium perman- ganate in alkaline mixtures gives azelaic acid and dioxystearic acids (M. & M., III. 6^7). 5. Concentrated sulphuric acid yields oxystearic acid. 6. Oleic acid combines with bromine to form dibromostearic acid (Allen, 11. 234). 7. Iodine combines with oleic acid to form addition products. [See AciDA.] Aciclum Phosphoricvim — i. Free orthophosphoric acid partially precipitates solutions of silver nitrate and lead acetate. 2. With a solution of ferric chloride it forms the colorless ferric phosphate, which is kept in solution by the liberated hydrochloric acid. Tannic acid or preparations containing it do not give the black color when added to this solution of ferric phosphate. 3. Orthophosphoric acid does not coagulate Qgg albumin or gelatin (difference from meta- phosphoric acid). 4. Phosphoric acid when added to a solu- tion of soluble phosphate or soluble pyrophosphate of iron produces a white precipitate of ferric phosphate or of pyro- phosphate of iron. A large excess of the free acid redissolves the precipitate. 5. The alkali phosphates precipitate neutral 28 INCOMPATIBILITIES IN PRESCRIPTIONS. solutions of nearly all other common metals. The precipitate is a di- or tri-metallic phosphate, and excepting lead, mercu- rous, antimony, and bismuth phosphates, is generally dissolved by phosphoric acid forming mono-metallic salts. 6. The ofificial sodium phosphate is frequently slightly alkaline and in that condition is apt to precipitate alkaloids from solutions of their salts. 7. Acetic acid transposes most of the insol- uble phosphates, except those of iron, aluminum, and lead. Dilute nitric, hydrochloric, and sulphuric acids transpose all phosphates, 8. The di- and tri-metallic phosphates, except those of the alkalies, are insoluble in water, but many are soluble in a solution of an alkali citrate. The mono-metallic phosphates are soluble in water to some extent. Phosphates are insoluble in alcohol. 9. Metaphosphoric acid precipitates solutions of silver nitrate, and lead acetate, and ferric chloride (difference from orthophosphoric acid), 10. It does not cause a precipitation when it is added to a solution of the soluble phosphate or pyrophosphate of iron. 11. It coagulates solutions of egg albumin or gelatin. 12. In aqueous solution metaphos- phoric acid slowly changes to orthophosphoric acid. 13. Pyrophosphoric acid precipitates solutions of lead acetate, ferric chloride, and gelatin, 14. The pyrophos- phates of the alkalies are soluble in water, and precipitate solutions of salts of nearly all other metals. 15. Most of the pyrophosphates are soluble in solutions of alkali pyrophos- phates as double salts. Alkali citrates also have a solvent effect. [See Acida.] Aciduin Picricum. — i. Picric acid and picrates pre- cipitate albumin, gelatin, and most alkaloids from aqueous solutions of their salts. 2. Salts of picric acid explode when struck or strongly heated (Richter, 678). 3. It is explo- sive when rubbed or heated with readily oxidizable substances such as sulphur. [See AciDA.] Aciduiu Salicylicuin. — i. Salicylic acid unites with alkali hydrates and with many metallic oxides to form INCOMPATIBILITIES IN PRESCRIPTIONS. 29 salts. 2. Salicylic acid liberates carbon dioxide from car- bonates. 3. Solutions of the salicylates in water, particularly if alkaline, become colored redbrown on exposure to the air. This can be prevented by the addition of a small proportion of sodium thiosulphate (Allen, III. part i. 58). 4. Sodium salicy- late precipitates solutions of lead acetate and silver nitrate as salicylates. 5. Salicylic acid and soluble salicylates with dilute solutions of ferric salts give a blue-violet to a violet- red color, depending upon the concentration. In rather acid solutions the color varies from that of the iron to brown or red. The color is destroyed by a large excess of a mineral acid or acetic acid. In nearly neutral solutions a precipitate of basic ferric salicylate is formed. 6. Sodium salicylate with copper sulphate gives a green solution from which the copper is not precipitated in dilute solutions by alkali hydrates. 7. Lime water gives a precipitate when mixed with a concentrated solution of sodium salicylate, 8. With bismuth subnitrate sodium salicylate in aqueous solution is said to give several compounds of bismuth and salicylic acid which have a color varying from white to red orange. The coloration, according to the author's experience, is not noticeable except after the lapse of considerable time. 9. A solution of potassium iodide with salicylic acid becomes yellow in one day, and after a few days it is brown and gives a test for iodine. 10. Concentrated nitric acid with salicylic acid gives nitrosalicylic acid; fuming nitric acid converts it into picric acid (Allen, III. part I. 52). II. Potassium chlorate with hydrochloric acid converts salicylic acid into tetrachloroquinone (N. D., 89). Chlorine forms mono- and di-chloro-salicylic acid (M. & M., III. 680). 12. A solution of iodine is slowly decolorized by sodium salicylate. Iodine gives mono-, di-, and tri-iodo- salicylic acid and tri-iodo-phenol (M. & M., in. 680). 13. Bromine water gives a precipitate with dilute solutions of salicylates. 14. Potassium permanganate oxidizes sali- cylic acid to formic acid and carbon dioxide. 15. Sodium salicylate with spirit of nitrous ether gives a yellow solution 30 INCOMPATIBILITIES IN PRESCRIPTIONS. which changes to redbrown in a few hours. 16. A mixture varying from a damp powder to a liquid results when salicylic acid or sodium salicylate is rubbed with exalgin, lead acetate, sodium phosphate, or urethane. In case of lead acetate there is a strong odor of acetic acid, indicating that acetic acid is liberated. 17. Salicylic acid is said to give a soft mass when it is rubbed with antipyrin, but according to the author's experiments this is not the case. 18. Sodium salicylate rubbed with antipyrin gives a powder which becomes damp and sticky. Some say that this is due to absorption of moisture from the air, while others say that chemical reaction takes place. 19. Soluble salicylates with solutions of quinine sulphate give a white curdy precipitate of quinine salicylate which is nearly insoluble in water. Sodium salicylate with a dilute solution (i : looo) of quinine sulphate gives a crystalline precipitate in a few days. 20. Mineral acids and some organic acids liberate salicylic acid from solutions of the sali- cylates. Salicylic acid, being but slightly soluble, is precipi- tated from a not too dilute aqueous solution. 21. A concen- trated aqueous solution of sodium salicylate (i : i) is said to be a good solvent for volatile oils, resinous substances, carbolic acid, guaiacol, creosote, thymol, menthol, and other bodies. 22. Salicylic acid is rendered more soluble in water by the presence of borax. The compound Ci^H,„NaBO, is said to be formed and deposited from strong solutions in the form of crystals, and also that the liquid soon undergoes decomposi- tion, acquiring a bitter taste (N. D., 88). 23. Salicylic acid is rendered more soluble in water by the presence of several neutral salts, such as the citrates, acetates, and phosphates of the alkalies, by potassium nitrate, and by sodium sulphite (Allen, III. part I. 51). [See AciDA.] Aciduin Stearicum. — i. Stearic acid combines with the alkali hydrates and carbonates to form stearates. 2. Nitric acid oxidizes it to succinic and other acids (M. & M., IV. 512). 3. Bromine water forms mono- and di-bromo- stearic acid (M. & M., IV. 513). INCOMPATIBILITIES IN PRESCRIPTIONS. 31 AcicUim Sulphuric villi. — i. Sulphuric acid transposes the salts of nearly all other acids. 2. Sulphuric acid and the soluble sulphates precipitate as sulphates solutions of salts of lead, barium, calcium (in concentrated solution), and stron- tium. 3. Sulphuric acid dissolves many metals with the evolution of hydrogen or sulphur dioxide, depending on the concentration of the acid. 4. With hypophosphorous acid it forms sulphurous acid and then sulphur. 5. Hydriodic acid with concentrated sulphuric acid forms iodine and sulphurous acid. 6. Concentrated sulphuric acid causes detonation with chlorates, with the evolution of the greenish-yellow chlorine peroxide. 7. With alcohol sulphuric acid forms ethylsul- phuric acid and then ether. 8. Water precipitates the aro- matics from the aromatic sulphuric acid. 9. The concen- trated acid with most organic matter forms a black mass, due to the extraction of the elements of water, leaving carbon. Some organic acids, many alkaloids, and some other com- pounds are not thus affected. 10. Dilute sulphuric acid does not cause as many decompositions as the concentrated. II. The sulphates of lead, barium, strontium, and calcium are nearly insoluble in water; silver and mercurous sulphates are sparingly soluble ; mercuric, antimony, and bismuth are soluble in acidulated water; the others are soluble in water. Sulphates are generally insoluble in alcohol. [See Acida.] Aciclum SuliJhurosuiii. — i. Sulphurous acid on ex- posure to air is slowly oxidized to sulphuric acid. 2. Sul- phurous acid does not usually precipitate solutions of metallic salts. The soluble sulphites — potassium, sodium, and am- monium — precipitate neutral solutions of salts of nearly all other metals. Sometimes sulphurous acid contains sulphuric acid which may cause reaction in certain cases. 3. Sulphites and sulphurous acid give a red color with a dilute solution of ferric chloride. The color is soon destroyed, due to the change of the ferric sulphite to ferrous sulphate. 4. Nitric or nitrous acid oxidizes sulphites to sulphates. 5. Hypo- phosphites in acid solution with sulphites form phosphoric ^2 INCOMPATIBILITIES IN PRESCRIPTIONS. ! acid and sulphur. 6. Sulphites with chlorine, or chlorates in acid solution, produce sulphuric and hydrochloric acids. 7. Silver salts in solution are first precipitated by sulphites and then reduced to metallic silver when warmed. 8. Arenic compounds are reduced to arsenous. 9. Perman- ganates in acid solution are reduced by sulphites to man- ganous compounds. 10, Chromates in acid solution are reduced to chromic salts. ii. Mercuric and mercurous nitrates are reduced to metallic mercury. Mercuric chlo- ride is slowly reduced to calomel and on heating to metallic mercury ; the sulphurous acid acts more quickly than the sulphites. 12. Sulphurous acid has a bleaching effect on organic coloring matters. 13. Sulphites are decomposed by nearly all acids, except carbonic, boracic, hydrocyanic, and in some instances hydrosulphuric. 14. The sulphites of the alkali metals are soluble in water; the others are insol- uble or sparingly so. The sulphites are insoluble in alcohol. [See AciDA.] Aciduni Tannicviiii. — i. An aqueous solution of tan- nic acid changes, forming gallic acid and probably some elagic and carbonic acids. The change is retarded or pre- vented by the presence of glycerin or alcohol (Caspari, 616). The solution gets darker on standing and this is hastened by alkalies, 2. Tannic acid in dilute solutions combines with the alkali hydrates and carbonates to form soluble tannates and these solutions soon become colored, varying from red to brown, green, or black. 3. Potassium hydrate or car- bonate with a concentrated solution of tannic acid gives a compound which is but slightly soluble in water, but dissolves in a certain excess of alkali (U. S. D., lOi). When potas- sium hydrate is added in excess to a solution of tannic acid tannoxylic acid or rubitannic acid is formed ; if the mixture is boiled tannomelanic acid is formed (A. D., 95). 4. Am- monia in its reactions resembles potassium hydrate (U.S.D., loi) but the precipitate is not nearly so great unless ammo- nium chloride has been previously added to the ammonia. INCOMPATIBILITIES IN PRESCRIPTIONS. t^^ 5. Sodium hydrate gives little or no precipitate. 6. A small amount of lime water added to a solution of tannic acid gives a precipitate which redissolves ; adding more Hme water the precipitate is white and permanent, changing to hght blue and then dark blue as more lime water is added ; a very large excess of lime water gives a precipitate which is pinkish. 7. Tannic acid precipitates as tannates solutions of salts of many of the metals, especially lead, silver, mercury, bismuth, and antimony. 8. The alkali tannates give pre- cipitates with solutions of salts of nearly all other metals. 9. With solutions of ferric salts tannic acid gives a solution or precipitate (depending on the concentration) of a dark blue-black to green-black color. The addition of enough of phosphoric acid to convert the iron into ferric phosphate prevents or destroys the color. Theoretically forty- five minims of 10 per cent, phosphoric acid is sufificient to convert one dram of the official tincture of ferric chloride into the phosphate. Practically it requires from one and a half to two times as much dilute acid as tincture, depending to some extent upon the amount of tannic acid, to prevent the forma- tion of the dark tannate of iron. 10. With purely ferrous salts in concentrated solution (not in dilute solution) it gives a white gelatinous precipitate, which quickly becomes blue on exposure to air. Nearly all commercial samples of ferrous sulphate contain some ferric salt. 11. A strong solution of tannic acid gives precipitates with concentrated sulphuric, hydrochloric, or phosphoric acids. These precipitates are supposed to be compounds of tannic acid with the respective acids, and are soluble in pure water but not in acidulated water (U. S. D., loi). 12. Saturated solutions of sodium chloride, calcium chloride, potassium acetate, and some other salts precipitate tannic acid from strong solutions. Precipitated by mineral salts or acids, tannic acid loses its astringency (Br. P., 21). 13. Potassium bichromate gives precipitates with most tannins (M. & M., IV. 634). 14. Potassium cyanide gives a green coloration with a solution 34 INCOMPATIBILITIES IN PRESCRIPTIONS. of tannic acid (M. & M., iv. 634). 15. With tannic acid and water iodine forms hydriodic acid, which combines with part of the tannic acid and remains in solution; the oxygen of the decomposed water combines with tannic acid and forms an insoluble compound ; the solution is capable of dis- solving iodine; the iodine in a liquid containing an excess of tannic acid does not give a blue color with starch (U. S. D., loi). 16. Nitric acid, chromic acid, chlorine, or bromine oxidizes tannic acid to formic and oxalic acids (A. D., 95). 17. Tannic acid reduces potassium permanganate. 18. Tannic acid with Fowler's solution or a solution of sodium arsenate gives a nearly white precipitate which with the liquid turns to a dark dirty green within a day. 19. Hydro- gen dioxide water with tannic acid shows no change at first but after a few days a light brown precipitate falls. 20. Tannic acid reduces salts of gold, silver, mercury, and copper (Allen, lii. part i. 89). 21, Triturated with potas- sium chlorate or other substances which yield their oxygen readily, tannic acid is liable to cause an explosion. 22. With spirit of nitrous ether, amyl nitrite, or nitrous acid tannic acid causes a decomposition and the formation of gaseous compounds some of which are oxides of nitrogen. The solution becomes deep red. 23. Tannic acid gives pre- cipitates with solutions of albumin, gelatin, glutin, or starch. 24. It precipitates as tannates nearly all alkaloids from aqueous or dilute alcoholic solutions of their salts ; the pre- cipitate is generally soluble in mixtures containing over fifteen to forty per cent, alcohol. The presence of some organic acids, acacia, or starch also tends to prevent the pre- cipitation. 25. Tannic acid preeipitates some glucosides, neutral and bitter principles. 26. It precipitates aqueous solutions of antipyrin. 27. Tannic acid slowly decomposes iodoform (U. S. D., 741). 28. All drugs containing tannic acid in large proportions will have the incompatibilities given above. Some of the drugs which contain notable quantities INCOMPATIBILITIES IN PRESCRIPTIONS. 35 of tannic acid are catechu, kino, krameria, logwood, gera- nium, blackberry-root bark and oak bark. [See AciDA.] Acidiim Tartaricuin. — i. When tartaric acid is added in excess to a rather strong solution of potassium hydrate or many of its salts, a crystalline precipitate of potassium bitartrate forms. 2. When tartaric acid is associated with boric acid it is not precipitated by potassium hydrate, even on adding acetic or hydrochloric acid (U. S. D., 104). Boric acid seems to act the part of a base with tartaric acid (Watts, I. 648). 3. Tar- taric acid in excess with a strong solution of ammonia gives a precipitate of ammonium bitartrate. 4. Potassium tartrate or Rochelle salt gives a precipitate of potassium bitartrate on adding many acids, the precipitate dissolving in a large excess of a mineral acid. 5. The soluble tartrates precipitate as tar- trates neutral solutions of salts of most metals. The precipi- tate is generally soluble in tartaric acid or mineral acids. Many of the tartrates form soluble compounds with the alkali hydrates, due to the formation of double tartrates. 6. Tar- taric acid decomposes potassium iodide, forming a tartrate and hydriodic acid which is slowly decomposed, liberating iodine. 7. Under certain conditions tartrates reduce salts of gold, silver, and platinum ; mercuric chloride becomes mer- curous chloride. 8. Potassium permanganate with an alkaline solution of a tartrate is reduced to manganese diox- ide, while the tartaric acid is converted into formic acid, car- bon dioxide, and water. 9. Chromates oxidize tartaric acid to formic acid, carbon dioxide, and water (M. & M., IV. 642). 10. Tartaric acid and tartrates tend to prevent the precipita- tion by alkali hydrates of the oxides and hydrates of the metals aluminum, antimony, bismuth, nickel, calcium, cobalt, chromium, copper, iron, lead, and zinc. 11. Tartrates in aqueous solutions have more or less solvent effect on certain salts which ordinarily are insoluble, as calcium phosphate and barium sulphate. 12. Tartrates are transposed by mineral acids. 13. Tartrates of the alkali bases are soluble in water. The bitartrates of potassium and ammonium are sparingly ^6 INCOMPATIBILITIES IN PRESCRIPTIONS. soluble. The manganous and ferric tartrates are soluble; calcium tartrate, sparingly soluble. The other tartrates are nearly insoluble. Tartrates are generally insoluble in alcohol. [See AciDA,] Aconitina. — i. Aqueous solutions of salts of aconitine are precipitated by alkali hydrates, the carbonates of the fixed alkalies, and by the general alkaloidal reagents. 2. Aconitine is decomposed by long standing or by heating with acids, alkalies, or water, forming benzoic acid and aconine. 3. Nitric acid gives a red-brown solution. 4. Ammonia, amyl nitrite, atropine, caffeine, ether, and morphine antag- onize its effect on the heart and respiration ; digitalis coun- teracts its heart action (Potter, 97). Strychnine and scopa- rine are also antagonists. [See under Alkaloids.] Adeps. — I. Lard oxidizes on exposure to air and light, becoming acid and rancid, and in this condition liberates iodine from potassium iodide. 2. Lard is decomposed by alkali hydrates or carbonates, forming glycerin, and oleates, stearates, and palmitates of the alkalies. [See Acidum Oleicum and Acidum Stearicum.] .^tlier. — I. In partly filled bottles, particularly in the presence of water, ether becomes acid, due to the formation of acetic acid. 2. After a few days ether with bromine forms ethyl bromide, bromal, and other products. 3. Hot nitric acid forms carbon dioxide, acetic and oxalic acids. 4. Chromic acid oxidizes it to acetic acid (M. & M., 11. 465). ^tlier Aceticiis. — i. Ethyl acetate in the presence of moisture decomposes into alcohol and acetic acid. 2. With alkaline hydroxides it yields alcohol and an acetate of the alkali. 3. It forms chlorinated compounds with chlorine. 4. With lime water and chlorinated lime it yields chloro- form. ^thyl Broiniclum. — i. Ethyl bromide is decomposed by light and air, forming alcohol, hydrobromic acid, and some free bromine (N. D., 141). 2. With alkali hydrates it gives ether and potassium bromide (M. & M., 480). 3, Ethyl INCOMPATIBILITIES IN PRESCRIPTIONS. -^y bromide with ammonia gives hydrobromate of ethylamine {Watts, II. 528). ^tliyleiii Bichloridum. — i. Dichlorethanewith water in the sunlight yields hydrochloric acid and acetic acid. 2. Ammonia water forms various ethylene amines (M. & M., II. 488). ^tliyl lodicluni. — i. Ethyl iodide or hydriodic ether on being exposed to air and light is decomposed with libera- tion of iodine fU. S. D., 1625). 2. Iodine is liberated by chlorine, nitric acid, and sulphuric acid. 3. Silver nitrate gives a precipitate of silver iodide (M. & M., 11. 499). Airol. — I . This oxyiodide of bismuth subgallate is slowly decomposed by water, particularly in the presence of heat, liberating iodine (Coblentz, 4). Albumin. — i. The coagubility of the different albumins varies. 2. Aqueous solutions of &^^ albumin are precipi- tated by heat and by many mineral acids, as hydrochloric, nitric, and meta-phosphoric (not by ortho- or pyro- phosphoric acid); 3. by salts of many heavy metals, as mercuric chlo- ride (prevented to a considerable extent by the presence of ammonium or sodium chloride or hydrochloric acid), alum, copper sulphate, gold chloride, and ferric chloride ; 4. by some neutral salts, as ammonium sulphate; 5. by hydro- gen dioxide water ; 6. by some organic acids, as tannic acid and substances containing it (not by gallic acid), lactic acid, picric acid, carbolic acid (not creosote), and trichlor- acetic acid ; 7. by some organic compounds, as alcohol (the precipitate is redissolved by dilution with water if the albumin has not been in contact with the alcohol too long), ether, collodion, resorcin, camphor, thymol, volatile oils, and coniine (not nicotine). Alcohol. — I. Alcohol precipitates albumin, acacia, and many inorganic salts from their aqueous solutions; to pre- cipitate the acacia the resulting mixture must contain about fifty or sixty per cent, alcohol before a permanent precipitate re- sults. 2. Strong nitric acid (not dilute) acts violently on alco- 38 INCOMPATIBILITIES IN PRESCRIPTIONS. hoi, forming nitric oxide, nitrous ether, carbon dioxide, alde- hyde, acetic and formic acids (M. & M., i. 97). 3. Chromic acid or a chromate in an acid solution oxidizes alcohol to aldehyde and acetic acid. 4. Potassium per- manganate in acid (not in alkaline) solution oxidizes it to aldehyde and acetic acid. 5. Chlorine is rapidly absorbed by alcohol and in sunlight may ignite the alcohol. The ultimate product is chloral alcoholate, there being a number of intermediate products, such as hydrochloric acid, aldehyde, ethyl chloride, acetic acid, chloral, etc. (M. & M., I. 97). 6. Bromine forms hydrobromic acid, water, ethyl bromide, bromal, and bromal alcoholate (M. & M., i. 97). 7. Mer- curic chloride is slowly reduced to calomel by alcohol (M. & M., I. 98). 8. Nitric acid with the nitrate of mercury or silver and strong alcohol forms the explosive fulminate of mercury or silver (M. & M., I. 97). 9. Concentrated mineral acids convert alcohol into esters and ethers. 10. Alcohol combines with many metallic salts, acting like water of crystallization (M. & M., I. 98). 11. With chloral hydrate alcohol forms chloral alcoholate which is not very soluble in elixir and less so in the presence of potassium bromide. 12. Alcohol sometimes contains traces of aldehyde or other impurities which are darkened by alkali hydrates. 13. The official alcoholic preparations, except those mentioned in the following classes, give precipitates when mixed with water, the precipitate sometimes being the active principle and sometimes inert matter: tinctures, except acetate of iron, chloride of iron, an old tincture of iodine, and deodorized tincture of opium ; fluid extracts, except chestnut ; spirits, except nitrous ether, ammonia, whiskey and brandy ; wines, except white, red, and antimonial. 14. Water generally causes a precipitation, when mixed with alcoholic solutions of the following substances: free alkaloids, alkaloids combined with any of the general alkaloidal reagents, glucosides, neu- tral and bitter principles, salicylic, gallic, or benzoic acid, volatile oils, resins, camphors, oleoresins, or balsams. 15. INCOMPATIBILITIES IN PRESCRIPTIONS. 39 Among the many substances which alcohol generally dis- solves may be mentioned acetates (except mercurous and silver), benzoates, bromides, chlorides (except potassium, sodium, ammonium, lead, silver, and mercurous), iodides (except lead, silver, and mercurous), nitrates (except potas- sium, lead, and bismuth), salicylates (except mercury and bismuth), deliquescent salts (except potassium carbonate), acids, alkali hydrates, alkali hypophosphites, phosphorus, sulphur, iodine, organic and inorganic acids (except arsenous), hydrocarbons and carbon derivatives, volatile oils, phenols, camphors, resins [see under Resinae], oleoresins, balsams, alkaloids and their salts, glucosides, and neutral principles. Alkalies. — The following preparations contain an alkali hydrate or carbonate : ammonia water, stronger ammonia water, bismuth and ammonium citrate, fluid extracts of gly- cyrrhiza and senega, saccharated carbonate of iron, ammonia liniment, lime liniment, lime water, solution of potassium hydrate, solution of sodium hydrate, solution of potassium arsenite, mass of carbonate of iron, compound iron mixture, chalk mixture; mixture of rhubarb and soda, pills of carbon- ate of iron, spirit of ammonia, aromatic spirit of ammonia, syrup of lime, ammoniated tincture of guaiac, ammoniated tincture of valerian, and syrup of rhubarb. [See HYDRATES, Fixed Alkali and Hydrate, Volatile Alkali.] Alkaloids. — i. Alkaloids combine with mineral acids and acetic and citric acids to form salts which are generally soluble in water or alcohol, but insoluble in ether, chloroform, benzol, petroleum ether, carbon bisulphide, or oils. In com- bination with most other organic acids the alkaloids form salts that are not generally soluble in water. 2. Alkaloids combined with acids and dissolved in water or very dilute alcohol are generally precipitated as free alkaloids by solu- tions of alkali hydrates or carbonates and by borax. Solu- tions of potassium arsenite, sodium phosphate and sodium arsenate are slightly alkaline and may precipitate the free alkaloid. M. Christiaens says : All salts whose reaction to 40 INCOMPATIBILITIES IN PRESCRIPTIONS. litmus is alkaline, whatever be their chemical function, pre- cipitate the alkaloids from their salts (D. C, XXXVIII. 59). Ammonium carbonate and the bicarbonates of potassium and sodium frequently do not cause precipitation. 3. The alkaloidal salts are generally precipitated from aqueous solution, combined with the precipitant, by soluble salicylates, benzo- ates, bichromates, iodides, bromides, and by the following general alkaloidal reagents: tannic acid, picric acid, iodine in solution of potassium iodide, bromine in solution of potassium bromide, potassium mercuric iodide (Mayer's reagent), potassium bismuthic iodide, mercuric chloride, platinic chloride, gold chloride, and phosphomolybdic acid. The presence of from twenty to fifty per cent, of alcohol will nearly always prevent the precipitation. 4. In the presence of acacia some alkaloids are not precipitated from dilute aqueous solutions of their salts by tannic acid, potassium mercuric iodide, or sodium phosphomolybdate (Allen, I. 353). Starch dissolved by boiling in water has a similar effect with the potassium mercuric iodide. 5. Some alkaloidal salts are thrown out of solution by the presence of considerable quanti- ties of very soluble salts, e.g., strychnine hydroiodide by potassium iodide. 6. Some alkaloids are strong reducing agents ; most alkaloids are decomposed by oxidizing agents. 7. The free alkaloids are generally only sparingly soluble in water, except atropine, caffeine, codeine, nicotine, and coniine, but are generally soluble in alcohol, ether, or chloro- form. A few are soluble in excess of solutions of fixed alkali hydrates, e.g., morphine; a few are soluble in excess oi ammonia water, e.g., quinine. 8. A strong solution of chloral hydrate dissolves morphine, quinine, and many other alka- loids (U. S. D., 367). The solubility of the salts of the alka- loids is also increased. Dilution with water may cause a pre- cipitation of the alkaloid. Aloiiiuni. — I. Concentrated solutions of aloin are slowly precipitated by a solution of lead subacetate (not the neutral lead acetate), more quickly if the mixture is heated. The INCOMPATIBILITIES IN PRESCRIPTIONS'. 41 liquid is turned brown. 2. An aqueous solution of aloin with ferric chloride gives a green-black to a brown-black color. 3. With solutions of alkali hydrates aloin gives an orange ta a red color, and is readily decomposed. 4. Concentrated nitric acid gives a red color with barbaloin or nataloin (not with socaloin), and by further action chrysammic, picric, and oxalic acids are formed. 5, Spirit of nitrous ether gives a red solution with aloin, even in the presence of a large amount of water. Aliiinen, — i. Alum in solution is precipitated as alumi- num hydroxide by the alkali hydrates and their carbonates^ borax, and lime water. Citrates, tartrates, glycerin, sugar, and acacia tend to prevent precipitation. 2. The alkali phosphates give the insoluble aluminum phosphate. Citrates and tartrates tend to prevent precipitation. 3. With tartaric acid it gives a precipitate of potassium bitartrate. 4. Tannic acid causes a slight precipitation. 5. Alum is slightly acid to litmus. 6. Adding a soluble carbonate to a solution of alum produces an efTervescence, due to the liberation of car- bon dioxide. 7. Alum has the incompatibilities of the sol- uble sulphates. [See AciDUM Sulphuricum.] Alumini hydras. — Aluminum hydrate, especially when freshly precipitated, removes suspended solid matter and coloring matter in solution from liquids. Aluinnol. — i. A solution of alumnol gives a precipitate of aluminum hydrate when treated with alkalies, the precipi- tate being soluble in excess of a fixed alkali (M. M. R., iv. 266). 3. It is precipitated by a solution of albumin or gelatin, the precipitate being soluble in excess of these sub- stances (M. M. R., IV. 266). 3. Silver nitrate is decomposed by it with the separation of metalHc silver (M. M. R., iv. 266). Animonii Benzoas. [See Acidum Benzoicum and Ammonium.] Ammoiiii Bromidum. [See Acidum Hydrobromi- cuM and Ammonium.] Ainiiioiiii Carbonas. — i. Ammonium carbonate with 42 INCOMPATIBILITIES IN PRESCRIPTIONS. calomel gives a black compound, dimercurous ammonium chloride, having the formula NH^Hg^Cl. 2. With a solution of mercuric chloride it gives a white precipitate of ammoniated mercury, NH,HgCl. 3. It gives no precipitate with mag- nesiun salts, except in concentrated solutions. 4. The pre. cipitate with copper or silver salts is dissolved by an excess of the carbonate. 5. Ammonium carbonate does not precip- itate as many of the alkaloids from solutions of their salts, as do the carbonates of potassium and sodium. Some of the alkaloids not precipitated are atropine, hyoscyamine (except in strong solution), nicotine, coniine, codeine, and caffeine. 6. Ammonium carbonate with resorcin in solution gives a red-brown solution at first which changes to deep blue in a day or two. 7. Excepting the reactions noted above, ammonium carbonate acts similarly to potassium or sodium carbonate. [See Carbonates and Ammonium.] Aniinonii Cliloridvini. — i. An aqueous solution is decomposed by chlorine, forming hydrochloric acid and the explosive nitrogen chloride (M. & M., I. 202). 2. Ammo- nium chloride aids the solution of several salts that are more or less insoluble ordinarily. [See AciDUM Hydrochlori- •CUM and Ammonium.] Amnionii lodicluin. — i. Ammonium iodide very frequently contains free iodine, and it would then have the incompatibilities of iodine. [See lODUM, AciDUM Hydri- odicum, and Ammonium.] Amnionii Nitras. [See Acidum Nitricum and Am- monium.] Animonii Pliosplias. [See Acidum Phosphoricum and Ammonium.] Animonii Valerianas. — Ammonium valerianate, in concentrated aqueous solution with sulphuric acid, gives an •oily layer of valerianic acid. [See AMMONIUM.] Ammoiiiiim. — i. Ammonium compounds, with solutions of the fixed alkali hydrates or carbonates, or with the hydrates of barium, calcium, or strontium, give free am- INCOMPATIBILITIES IN PRESCRIPTIONS. 43 TOonia. 2. Some ammonium salts with chlorine gas give ex- plosive nitrogen chloride. 3. Certain ammonium salts, such as the acetate, citrate, and chloride, in aqueous solution may act as solvents for otherwise insoluble compounds. [For ammonia water see Hydrate, Volatile Alkali.] Aiiiyl Nitrite. — i. Amyl nitrite is decomposed slowly by light and air, becoming acid (Allen, I. 159). 2. With alcohol or alcoholic preparations, it gradually forms ethyl nitrite and amyl alcohol (U. S. P., 40). 3. With potassium hydrate it forms potassium nitrite and amyl alcohol (Allen, I. 159). 4. Belladonna, brucine, chloroform, digitalis, mor- phine, picrotoxin, and strychnine are somewhat antagonistic physiologically to amyl nitrite. [See AciDUM NiTROSUM.] Ainylimi. — i. Starch in aqueous solution is precipitated by strong alcohol, tannic acid, or lead subacetate. 2. Iodine with starch forms the blue-black iodide of starch. 3. With solutions containing over five per cent, of an alkali hydrate starch forms a soluble compound. 4. Acids grad- ually change it to dextrin. Diastase has a similar effect. 5. In solution starch to some extent prevents the precipita- tion of alkaloids by potassium mercuric iodide and tannic acid. Antiinonii et Potassii Tartras. — i. Tartar emetic in aqueous solution is precipitated by hydrochloric, nitric, or sulphuric acid, forming a basic chloride, nitrate, or sulphate of antimony, together with some potassium bitartrate. Tar- taric acid prevents this precipitation to some extent. 2. The alkali hydrates or their carbonates, with solutions not too dilute, give a white precipitate of antimony oxide. Citrates, tartrates, glycerin, sugar, and acacia prevent precipitation. 3. Lime water throws down a precipitate consisting of the mixed tartrates of calcium and antimony (U. S. D., 177). 4. The salts of most metals, being precipitated by normal tartrates, are incompatible with tartar emetic. 5. Strong alcohol throws tartar emetic out of aqueous solution. 6. Tannic acid gives a precipitate of tannate of antimony. 7. 44 INCOMPATIBILITIES IN PRESCRIPTIONS. Gallic acid precipitates concentrated solutions of tartar emetic 8. In aqueous solution mercuric chloride is reduced to calo- mel which is precipitated. 9. Solutions of lead acetate, silver nitrate, albumin, and soap give precipitates with tar- tar emetic. 10. Opium, alcohol, and ether are physiological antagonists. Antiiuoiiii Sulphiduin. — i. Triturated with a strong oxidizing agent, as potassium chlorate, sulphide of antimony- may cause an explosion. 2. By exposure to air it is partially converted into an oxide (U. S. D., 182). Antipyriiiuiii. — i. Antipyrin is neutral to litmus, but forms salts with acids by direct addition (N. D., 227). 2. An aqueous solution with a strong solution of sodium hydrate gives a white precipitate. 3. With a solution or tincture of ferric chloride antipyrin gives a red color, and according to some writers the mixture should not be dis- pensed. The red color is destroyed or prevented by an excess of mineral acids or acetic acid. 4. With commercial ferrous sulphate it gives a red color, due to the ferric salt which is present. With strictly ferrous salt the solution is colorless. 5. A mixture of two drams of antipyrin with one ounce of simple syrup and one ounce of syrup of ferrous iodide (free from iodine) soon gives a red liquid and in a few hours a red precipitate. The precipitate becomes crystalline and forms comparatively large ruby-red prismatic crystals after a few days. 6. Antipyrin gives a green color with a solution of copper sulphate. 7. With a strong solution of antipyrin lead subacetate forms a precipitate. 8. In the presence of m.oisture calomel is slowly turned dark by antipyrin, but if sodium bicarbonate is mixed with it the color is changed at once. From Werner's experiments it would appear that metallic mercury, mercurous oxide, mercuric chloride, and antipyrin hydrochloride are formed, but the mercuric chloride will combine with the antipyrin in all probability (Ph. E., XVII. 196). 9. An aqueous solution of antipyrin is precij)i- tated by a solution of mercuric chloride or by Donovan's INCOMPATIBILITIES IN PRESCRIPTIONS. 45 solution. lo. Alum and tartar emetic are both said to be incompatible with antipyrin, but rubbing these with antipyrin or mixing aqueous solutions produces no apparent change. II. A dilute solution of antipyrin with nitric acid gives a yellow color, passing into crimson on warming. 12. A solu- tion of iodine gives with a solution of antipyrin a red-brown precipitate which dissolves in an excess of antipyrin, forming a colorless solution. There is probably formed the colorless iodoantipyrin (iodopyrin) or the di-iodoantipyrin. If more iodine is added a permanent precipitate is formed which is soluble in alcohol. 13. Bromine water gives a precipitate which is soluble at first but remains permanent on adding more bromine. 14. Antipyrin slowly reduces potassium permanganate, precipitating manganese dioxide. 15. Chro- mic acid gives an orange precipitate with a strong solution of antipyrin. 16. An aqueous solution of antipyrin gives a precipitate with tannic acid or preparations containing it in considerable proportions, by picric acid and by most of the general alkaloidal reagents. [See under Alkaloids.] 17. Spirit of nitrous ether with antipyrin gives a green solution, and on standing green crystals are formed if the solution is concentrated. The reaction does not take place as quickly when the spirit is neutral as when it is acid, and by having a little sodium bicarbonate present the reaction may be pre- vented for several days or weeks. The green compound is iso-nitroso-antipyrin. The experiments of Drs. H. C. Wood and John Marshall, as well as those made by other experi- menters, go to show that this compound is not a dangerous one, as Drs. Wood and Marshall gave it in doses of fifteen grains, repeated several times at intervals of an hour (D. C, XXXIII. 107). According to these investigators there is a small amount of cyanogen evolved, the quantity being so small that no danger need be apprehended. Other nitrites act similarly. 18. Crystallized carbolic acid when triturated with antipyrin gives an odorless liquid called phenopyrin. On mixing aqueous solutions of these two substances a turbidity 46 INCOMPATIBILITIES IN PRESCRIPTIONS. results, and an oily liquid settles to the bottom in a few hours, 19. Triturating chloral hydrate and antipyrin together in proper proportions forms the liquid monochloral-antipyrin, from which hypnal is made. Moderately dilute aqueous solu- tions of antipyrin and chloral hydrate can be mixed v/ithout separation. 20. When antipyrin and sodium salicylate are rubbed together a mass or liquid is formed after a time, the length of time seeming to depend on the amount of moisture in the atmosphere. It has been suggested that the simple nnixture is hygroscopic (N. D., 227), but more probably a chemical reaction takes place. Rubbing with salicylic acid does not give a mass or liquid. 21. Antipyrin gives a liquid when it is triturated with acetamid, bromal hydrate, chloral alcoholate, pyrocatechin, pyrogallol, resorcin, thymol, or urethane. 22. Rubbing antipyrin and acetanilid together is said to produce a mass. A slight dampness, which usually quickly disappears, is produced by hard trituration. Some- times liquefaction results, seeming to depend on the condition •of the atmosphere. 23. Triturated with bromal hydrate or salol it gives a damp powder. 24. Antipyrin dissolved in wine causes a gradual precipitation of the coloring matter (N. D., 227). 25. Antipyrin increases the solubility of qui- nine sulphate in water, and at the same time destroys the fluorescence and prevents the green coloration which quinine gives with bromine water followed by ammonia water. 26. The solubility of caffeine is said to be increased by antipyrin. 27. Antipyrin is said to be incompatible with sodium bicar- bonate, ammonia water, hydrocyanic acid, arsenic, and benzoates. Apoiuorpliiiiee Hydrocliloricluin. — i. An aqueous solution of apomorphine hydrochloride rapidly becomes green in color ; the exact change which takes place has not been determined. 2. An aqueous solution is precipitated by the alkali hydrates and carbonates and by lime water as the free alkaloid, white at first, but quickly turning green or black. 3. It is precipitated by tannic acid, picric acid, and INCOMPATIBILITIES IN PRESCRIPTIONS. 47 nearly all the alkaloidal reagents. [See Alkaloids.] 4. With a concentrated solution of ferric chloride it gives a red precipitate, turning black. 5. Concentrated nitric acid added to the crystals gives a red solution. 6. Apomorphine hydro- chloride in aqueous solution reduces iodates, permanganates, and silver nitrate. 7. Strychnine, chloral hydrate, and chloroform are somewhat incompatible with it physiologi- cally. Aqua.— Water precipitates from their alcoholic solutions oils, many free alkaloids or alkaloids combined with general alkaloidal reagents, some glucosides, some neutral and bitter principles, resinous or fatty matter, inert extractive mat- ter, and nearly all compounds which are insoluble in water. Aqua Amnionise. [See Hydrate, Volatile Alka- li.] Aqua Aniygclalae Amarse. [See Acidum Hydro- CYANicu-M and Oleum Amygdala Amar^.] Aqua Camiiliorae. — The camphor in camphor water is sometimes thrown out of solution by dissolving in the water a large amount of some soluble salt as potassium bromide. Aqua Clilori. [See Chlorum.] Aqua Cinnanionii. [See Oleum Cinnamomi.] Aqua Creosoti. [See Creosotum.] Aqu?e. — The medicating or flavoring principle in some waters is thrown out of solution by dissolving certain very soluble inorganic salts in the water; e.g., camphor water gives a precipitate of camphor when potassium bromide is dissolved in it. Aqua Hydrogenii Dioxidi. — i. A solution of hydro- gen peroxide generally contains a free mineral acid, which has been added to aid preservation. In such a case the solution would have the incompatibilities of the acid. 2. Hydrogen dioxide slowly undergoes decomposition, liberating oxygen, and if the bottle is tightly corked a sufificient pres- sure may be produced to burst the bottle. 3. Hydrogen 48 INCOMPATIBILITIES IN PRESCRIPTIONS. dioxide is a strong oxidizing agent, changing mercurous compounds to mercuric, ferrous to ferric, arsenous to arsenic, hypophosphites to phosphates, and sulphites to sulphates. 4. It liberates sulphur from sulphides. 5. With reduced iron and water it gives a little effervescence, and in a few hours a brown precipitate of ferric hydrate or oxide. 6. Chromic salts in alkaline mixtures are oxidized to a chromate. A chromate in the presence of an acid is reduced to a chromic salt (M. & M., II. 723). 7. Caustic alkalies decompose hydro- gen dioxide, forming oxygen and water (M. & M., II. 724). 8. Ammonia in solution forms ammonium nitrite (M. & M., II. 723). 9. Iodides are oxidized liberating iodine. 10. Bro- mine is liberated from hydrobromic acid. 1 1. With chlorine hydrogen dioxide forms hydrochloric acid and oxygen (M. & M., II. 724). 12. Hydrogen dioxide reduces potassium permanganate and is itself reduced ; the products in a solu- tion acidulated with sulphuric acid are manganous sulphate, potassium sulphate, water and oxygen. 13. It reduces gold, silver, mercuric mercury, and platinum from their oxides (P. & J., 212). 14. Hydrogen dioxide unites with some acids as phosphoric, sulphuric, nitric and hydrochloric, forming mixtures in which it is less easily decomposed (Watts, III. 197). 15. Reaction takes place when hydrogen dioxide water and formic aldehyde are mixed, producing formic acid. 16. It bleaches litmus and most organic colors. 17. Hydro- gen dioxide slowly reacts with alcohol. 18. It gives a blue color with a tincture of guaiac if the guaiac has not been exposed to air and light too long. 19. With tannic or gallic acid it slowly gives off some gas and colors the solution yellow brown. 20. Hydrogen dioxide oxidizes carbolic acid to pyrocatechin, hydroquinone and quinone (M. & M., III. 832). A mixture of hydrogen dioxide water and carbolic acid becomes yellow to red brown in a few hours. 21. Hydro- gen dioxide changes glycerin to oxalic acid and carbon dioxide. 22. It coagulates a solution of albumin (U. S. D., 214). 23. Some substances such as ammonia, hydrocyanic INCOMPATIBILITIES IN PRESCRIPTIONS. 49 acid, tobacco, aconite, and most narcotic substances are unaffected by it and restrain its oxidizing influence on other bodies (U. S. D., 213). 24. Quite a number of substances decompose hydrogen dioxide into water and oxygen while they themselves are not affected. Some examples of these are manganese dioxide, sodium sulphate, potassium bro- mide, potassium chloride, charcoal, and some organic sub- stances (M. & M., II. 724). Aqua Meiitlife Piperitse. [See Oelum Mentha Piperita.] Aqua Pinientse. [See Oleum Pimento.] Argeuti Nitras. — i. Silver nitrate is easily changed to the oxide or metallic silver by light and organic matter. 2. Silver nitrate in aqueous solution is precipitated as the gray-brown silver oxide by the hydrates of potassium, so- dium, and ammonium, the precipitate being soluble in ammonia water. 3. The alkali carbonates precipitate the yellow-white silver carbonate. 4. Hydrochloric acid and the soluble chlorides precipitate the white silver chloride. 5. Sol- uble arsenites precipitate the yellow silver arsenite. 6. Sol- uble arsenates precipitate the red-brown silver arsenate. 7. Sodium phosphate precipitates the yellow silver phosphate. 8. Borax precipitates silver borate. 9. The soluble bro- mides, iodides, and cyanides precipitate the silver bromide, iodide, and cyanide, the iodide and cyanide being soluble in excess of the precipitant. 10. Chromates precipitate the red-brown silver chromate. 11. Potassium permanganate with not too dilute solutions of silver nitrate gives a precipi- tate of silver permanganate. 12. It is reduced to metallic silver by metallic zinc, copper, tin, mercury, and lead ; by hypophosphites and sulphites; in alkaline mixtures, by arsenites, manganous salts, antimonious salts ; by ferrous sulphate in the cold. 13. Tannic acid precipitates the sil- ver tannate. 14. Soluble citrates give precipitates of silver citrate. 1 5 . Soluble salicylates give precipitates of silver sali- cylate. 16. Morphine salts are precipitated by silver 50 INCOMPATIBILITIES IN PRESCRIPTIONS. nitrate with a red coloration. 17. Free cocaine gives a black precipitate, probably of silver oxide. 18. Silver nitrate in solution is reduced to the metallic condition by glucose, vol- atile oils, aromatic waters, tartrates, creosote, formalde- hyde, and many other organic substances, but not generally by alkaloids. 19. An alcoholic solution of silver nitrate gradually deposits metallic silver. 20. Silver nitrate heated with nitric acid and alcohol produces the violently explosive fulminate of silver (N. D., 279). 21. Most salts of silver, except the nitrate and chlorate, are insoluble or sparingly soluble in water. Arg-enti Oxidum. — i. Silver oxide readily parts with its oxygen, forming explosive mixtures with many substances. Triturated dry with sulphur, sulphide of antimony, sulphide of arsenic, phosphorus, tannic acid, creosote, and some other organic substances, it is liable to explode or cause ignition. 2. Moist silver oxide decomposes many metallic salts in solution, precipitating the metallic hydroxides, e.g., salts of bismuth, copper, iron, and mercury (M. &M., iv. 470). 3. Iodine in water forms silver iodide and iodic acid. 4. Chlorine forms silver chloride and chlorate. 5. A strong solution of silver oxide in concentrated ammonia forms the explosive silver nitride (Ag^N) on standing or by adding alcohol (M. & M., IV. 470). Aristol. — I. Aristol is decomposed by light and heat, liberating iodine. 2. It should not be mixed with bodies having a strong afifinity for iodine. Sulphuric acid decom- poses it* Arseni locliduui. — i. Iodide of arsenic in aqueous solu- tion decomposes into arsenous and hydriodic acids (U. S. P., 58). Iodine is also liberated. 2. Iodide of arsenic precipi- tates many alkaloids from solutions of their salts. 3. Its incompatibilities are similar to those of the soluble iodides and of arsenous acid. [See AciDUM Hydriodicum and AciDUM Arsenosum.] Arsenates. [See Acidum Arsenicum.] INCOMPATIBILITIES IN PRESCRIPTIONS. 51 Arsenites. [See Acidum Arsenosum.] Asai>rol. — i. When a neutral solution of quinine sul- phate or hydrochloride is poured suddenly into a solution of asaprol, there forms on the surface of the liquid a resinous body adhering to the walls of the vessel. If the asaprol solu- tion is gradually poured into the quinine solution a precipi- tate forms and settles. 2. Asaprol being a calcium salt, has the incompatibilities of calcium salts (D. C, xxxviii. 107). 3. A solution of asaprol is precipitated by antipyrin. Atroi>iiia. — i. Atropine is precipitated from concen- trated aqueous solutions of its salts as the free alkaloid by alkali hydrates and the carbonates of the fixed alkalies (not ammonium carbonate or the bicarbonates). 2. It is precipitated by the general alkaloidal reagents, except platinic chloride. [See Alkaloids.] 3. By continued heating with alkali hy- drates, acids, or water, atropine is decomposed, forming tro- pine and tropic acid. 4. Chromic acid converts it into benzoic acid(M. &M., i. 362). 5. The precipitation by gold chloride is prevented to some extent by the presence of sodium hypo- sulphite, 6. Some of the antagonists of atropine are mor- phine, pilocarpine, physostigmine, aconitine, chloral hy- drate, hydrocyanic acid, muscarine, quinine, bromal hy- drate, and Phytolacca. Auri et Soclii Cliloriclvini. — i. Gold and sodium chloride precipitates many of the alkaloids from solutions of their salts as double compounds. The addition of sodium thiosulphate to the chloride before mixing with the alkaloidal solution tends to prevent precipitation. If one fourth of a grain of sodium thiosulphate be dissolved in one dram of water and added to one eighth of a grain of gold and sodium chloride dissolved in one dram of water and this added to one eighth of a grain of strychnine sulphate in two drams of water, no precipitation will take place at once or for several days. Using one half as much water as above stated, a pre- cipitate may be slowly formed. If one fourth the amount of water is used precipitation will usually take place within a. 52 INCOMPATIBILITIES IN PRESCRIPTIONS. •day. 2. Potassium iodide added to a solution of gold ■chloride (the latter being in excess) precipitates the yellow aurous iodide and liberates iodine. But if the solution of gold chloride is added to the potassium iodide solution (the latter being in excess), there is first formed a dark green solu- tion of potassium auric iodide, then a precipitate of auric iodide which is instable, decomposing in pure water forming aurous iodide (P. & J., 154). 3. Gold chloride combines with and precipitates albumin. 4. Gold chloride in solution is reduced to metallic gold by metallic silver, mercury, cop- per, and iron; 5. by mercurous salts, arsenites, ferrous sulphate, and many organic substances; 6. by hypophos- phorous, sulphurous, nitrous, oxalic, and tannic acids; 7. by light and heat. 8. Atropine and morphine are some- what antagonistic physiologically. Bariimi. — Barium salts in aqueous solution are precipi- tated by sulphuric acid and soluble sulphates, by aqueous solutions of phosphates, tartrates, oxalates, carbonates, chromates, or tannic acid, the precipitate being barium sulphate, phosphate, tartrate, oxalate, carbonate, chromate, ■or tannate. Belladonna. [See Atropina.] Benzaldehydum. [See Oleum Amygdala Ama- B'enzoates. [See Acidum Benzoicum.] Bismuthi et Aininonii Citras. — i. Citrate of bis- muth and ammonium in aqueous solution is precipitated as the bismuth citrate by most mineral acids and the stronger organic acids. 2. It is not readily precipitated by the fixed alkali hydrates, but these on heating liberate ammonia. Bismuthi Salicylas. — i. Bismuth salicylate with a solution of a ferric salt gives a violet color. Bismuthi Subgallas. — i. Bismuth subgallate or der- matol is decomposed by strong acids with liberation of ;gallic acid. Bismuthi Svihnitras. — i. Bismuth subnitrate is con- INCOMPATIBILITIES IN PRESCRIPTIONS. 53 verted into the hydrate by solutions of the alkali hydrates. 2. In the presence of water the alkali carbonates and bicarbonates convert it into the subcarbonate, and at the same tinne some carbon dioxide is liberated. 3. Soluble iodides change bismuth subnitrate to an iodide. [See No. 9, under AciDUM Hydriodicum.] 4. Hypophosphites in neutral or alkaline mixtures reduce bismuth subnitrate to a form of bismuth having a quantivalence of two (P. & J., 220), a black compound being formed. 5. Chlorine or chlorinated lime in alkaline mixtures convert the bismuth into the reddish peroxide (P. & J., 90). 6, Tannic acid in the presence of water slowly forms the yellow tannate of bismuth. 7. With a solution of sodium salicylate bismuth subnitrate is said to form a series of nitro-salicylates, varying in color from white to red orange. Mixtures of these in various proportions made in the author's laboratory showed no perceptible change even on standing. 8. Bismuth sub- nitrate is soluble in glycerin, but should not be triturated with it for fear of an explosion (Scoville, 226). Borates. [See Acidum Boricum and SoDii Boras.] Bromal Hydras. — i. Bromal hydrate is decomposed by alkali hydrates, forming bromoform and a formate (N. D., 352). 2. With alcohol it forms bromal alcoholate {M. & M., I. 540). 3. It forms a liquid or mass when triturated with acetamid, antipyrin, borneol, carbolic acid, euphorin, exalgin, menthol, pyrocatechin, urea, or ure- thane. With diuretin or methacetin it gives a damp powder. Bromides. [See Acidum Hydrobromicum.] Bromoforinum. — i. Bromoform turns yellow in the light. 2. Potassium hydrate converts it into a bromide and a formate of potassium. 3. With alcoholic potash bromoform is decomposed, producing potassium bromide, carbon monoxide, ethylene, and water (Allen, I. 184). Broinvim. — i. Bromine with alkali hydrates forms bro- mides and bromates. 2. With sulphites it forms sulphates 54 INCOMPATIBILITIES IN PRESCRIPTIONS. and bromides. 3. With hypophosphites it forms phos- phates and bromides. 4. Metalhc mercury and mercurous compounds are oxidized to mercuric compounds. 5. Ar- senites are converted into arsenates. 6. Ferrous salts are converted into ferric salts, and in alkahne mixtures into fer- rates. 7, Bromine bleaches vegetable colors. 8. It com- bines with many fixed oils containing olein, forming addition products, 9. With oil of turpentine and some other vola- tile oils it is liable to react violently and may cause ignition. 10. Bromine in water gradually forms hydrobromic acid and oxygen (M. & M., I. 536). 11. An alcoholic solution is gradually decolorized, forming hydrobromic acid. 12. With hydrogen dioxide oxygen is evolved. 13. Bromine colors starch paste yellow. Butyl Chloral Hydras. — i. Butyl chloral hydrate (erroneously called croton chloral hydrate) gradually under- goes decomposition in aqueous solution, 2. With alkalies it is decomposed, producing a formate and propylic chloroform, which splits up with the formation of a chloride of the alkali and dichloride of allylene (Allen, I. 176). 3. It liquefies or gives a soft mass when triturated dry with acetamid, carbolic acid, exalgin, menthol, pyrocatechin, or urethane. With antipyrin, camphor, or thymol it is said to liquefy, but a powder was obtained in each case. 4. Picrotoxin is said to be physiologically incompatible with it, as are atropine, strychnine, and caffeine. Cacliiiiuin. — The soluble cadmium salts in aqueous solution are precipitated by the alkali hydrates, forming white cadmium hydrate ; by alkali carbonates, forming the white cadmium carbonate ; by the soluble sulphides and hydrosulphuric acid, as the yellow cadmium sulphide; by the alkali chromates, as the yellow cadmium chromate ; by the soluble phosphates, as the white cadmium phosphate. Caffeliia. — i. Caffeine does not readily combine with dilute acids, although it unites with concentrated acids. The salts are easily decomposed by water, alcohol, or ether. INCOMPATIBILITIES IN PRESCRIPTIONS. 55 "2. Caffeine in moderately dilute solutions is not precipitated by the alkali hydrates or carbonates or the general alka- loidal reagents, except tannic acid, phosphomolybdic acid, and mercuric chloride. 3. Warmed with alcoholic potas- sium hydrate it forms methylamine, carbon dioxide and a little ammonia (N. D., 362). 4. The solubility of caffeine is increased by the presence of sodium salicylate, sodium benzoate, or antipyrin (Extra Pharm., 89). 5. Chloral hy- drate, physostigma, opium, and tobacco are somewhat antagonistic physiologically. Calcium. — i. The soluble calcium salts in concentrated solutions are precipitated by the fixed alkali hydrates as calcium hydrate; 2. by soluble sulphates in not too dilute solutions as sulphate; 3. by soluble carbonates, phos- phates, oxalates, or tartrates as calcium carbonate, phos- phate, oxalate, or tartrate. 4. Soluble citrates on heating precipitate the calcium citrate. Calcii Bromiduni. [See Calcium and Acidum Hydrobromicum.] Calcii Carbonas. [See Calcium and Carbonates.] Calcii Hypophosphis. — i. Calcium hypophosphite in aqueous solution gradually changes to calcium phosphate. 2. Excess of sugar throws calcium hypophosphite out of solu- tion (Scoville, 227). 3. The presence of hypophosphorous acid increases its solubility in water. [See CALCIUM and Acidum Hypophosphorosum,] Calcii Pliosplias — Calcium phosphate forms soluble compounds with nearly all acids except those which precipi- tate calcium salts. Calcii Sulphas. — Calcium sulphate is sparingly solu- ble in water. [See CALCIUM and AciDUM SULPHURICUM.] Calx. — I. Lime exposed to air absorbs carbon dioxide and water. 2. It combines with water to form calcium hydrate, which has many of the properties of the fixed alka- lies. [See Calcium and Hydrates, Fixed Alkali.] Calx Clilorata. — i. Chlorinated lime contains calcium 56 INCOMPATIBILITIES IN PRESCRIPTIONS. hypochlorite which is very easily decomposed by mineral acids and carbon dioxide, liberating chlorine. 2. It converts sugar, starch, cellulose, and similar substances into formic acid (U. S. D., 294). 3. It acts energetically on volatile oils, forming chloroform (U. S. D., 294). 4. Mixed with glycerin it reacts violently, giving off white fumes and turn- ing the mass brown. The ultimate products of the oxida- tion are oxalic acid and carbon dioxide. 5. With organic substances in a dry state chlorinated lime causes gradual decomposition with the development of heat, and may cause explosion. [See Chlorum, Calcium, and Acidum Hydro- CHLORICUM.] Calx Suli)liiirata. — Sulphurated lime is decomposed by mineral acids and carbon dioxide, liberating hydrogen sul- phide. Cainbogia. — i. Gamboge gives an orange-red solution with a solution of sodium or potassium hydrate and the color caused by the latter reagent changes to yellow brown. 2. With ammonia water it gives a yellow solution, changing to red and finally brown. 3. With a tincture of iron it gives a black-brown solution. Cainpliora. — i. Camphor when oxidized by nitric acid forms camphoric acid which is insoluble in water, and camphor- onic acid which is soluble (M. & M., I. 669). 2, With chromic acid it forms camphoronic acid (M. & M., i. 669). 3. Potassium permanganate in alkaline solution converts cam- phor into camphoric acid (M. & M., I. 669). 4. Bromine unites with it to form the crystallizable instable dibromide of camphor, which on heating breaks up into hydrobromic acid and monobromated camphor (Allen, II. 447). 5. Iodine acts on camphor, when heated, with evolution of hydri- odic acid, and formation of cymene, carvacrol, laurine. and other bodies the nature of which has not been determined (R. & S., III. part V. 427). Iodine dissolved with a large excess of camphor in alcohol still gives the iodine reaction with starch after several days. 6. Chlorine has no action on INCOMPATIBILITIES IN PRESCRIPTIONS. 57 camphor but in the presence of alcohol it forms chlorinated compounds (M. & M., I. 669). 7. Camphor absorbs the gases of hydrochloric acid, sulphur dioxide, and nitric peroxide, forming colorless liquids which are decomposed on adding water (Allen, II. 446). 8. Solutions of camphor in alcohol and ether increase the solubility of corrosive sublimate and the presence of this salt increases the solubility of camphor in these liquids (N, D., 388). 9. Camphor when heated with salicylic acid on the water bath forms an oily liquid, salicylated camphor, which solidifies on cooling (N. D., 389). 10. The odor of camphor covers up the odor of musk and is itself overcome by that of Tolu, asafoetida, and other similar substances. 11. When camphor and a resinous substance are rubbed together a soft mass is formed. 12. Camphor produces a liquid or soft mass when triturated with about an equal weight of the following sub- stances : carbolic acid, chloral alcoholate, chloral hydrate, euphorin, menthol, naphtol, pyrocatechin, pyrogallol, resorcin, salol, thymol, urethane, monochloracetic acid, or dichloracetic acid. Cainphora Moiiobroniata. — i. Monobromated cam- phor with nitric acid forms bromo-nitro-camphor and cam- phoric acid (M. & M., i. 670). 2. With alcoholic potash it forms camphor (M. & M., I. 670). 3. When triturated with carbolic acid, chloral alcoholate, chloral hydrate, euphorin, pyrocatechin, salol, or thymol it gives a liquid or soft mass. Cannabis Inclica. — i. Water added to an alcoholic extract of cannabis indica causes the precipitation of a large amount of resinous matter. This resinous matter is soluble in a concentrated aqueous solution of chloral hydrate. 2. Strychnine is somewhat antagonistic. Cantliaridin. — i. Cantharidin combines with alkalies, forming soluble cantharidates. 2. It is precipitated from solutions by neutral lead acetate, silver nitrate, mercuric chloride, and copper sulphate. 38 INCOMPATIBILITIES IN PRESCRIPTIONS. Carbo. — i. Charcoal absorbs many gases, such as am- monia, hydrogen sulphide, etc. 2. When mixed with solu- tions it absorbs and removes from solution tannic acid, many alkaloids, many glucosides, and a number of bitter and odorous principles, coloring matter, fusel oil; iodine, and many metallic salts (N. D., 406). 3. When triturated with oxidizing agents, such as potassium chlorate or potassium permanganate, there is danger of an explosion. Carbonates. — i. Carbonates are decomposed by all com- mon acids except hydrosulphuric and hydrocyanic acids, and by some metallic acid salts, with liberation of carbon diox- ide. 2. Solutions of potassium and sodium carbonates precipi- tate solutions of salts of all other common metals ; the precip- itate is a normal carbonate in case of silver, mercurous mer- cury, cadmium, ferrous iron, manganese, barium, stron- tium, and calcium ; it is a hydrate in case of tin, aluminum, ferric iron, and chromium ; it is an oxide in case of antimony ; it is a basic carbonate in case of lead, nickel, bismuth, copper, zinc, cobalt, magnesium, and mercuric mercury. 3. The carbonates of the alkalies precipitate as free alkaloids the aqueous solutions of most alkaloidal salts and decompose a few of the alkaloids. 4. In the presence of water bismuth subnitrate liberates carbon dioxide from the alkali carbon- ates. 5. Ammonium carbonate causes reactions similar to potassium carbonate, except with resorcin and salts of mer- cury, copper, silver, and alkaloids. [See Ammonii Car- BONAS.] 6. The carbonates of the alkalies are soluble in water. The other normal or basic carbonates are insoluble in water, although many are soluble in excess of carbon dioxide, forming bicarbonates. The carbonates are insoluble in alcohol. 7. The bicarbonates of the alkalies have about the same incompatibilities as the carbonates, although they do not pre- cipitate as many of the alkaloidal or metallic salts. 8. The pure bicarbonates do not precipitate solutions of salts of atropine, hyoscyamine, nicotine, quinine, quinidine, cocaine, coniine, codeine, brucine, or caffeine, unless the solution be INCOMPATIBILITIES IN PRESCRIPTIONS. 59 ■quite concentrated or heat be applied (Sohn), 9. Pure sodium bicarbonate does not precipitate solutions of silver nitrate or barium chloride (U. S. D., 1233). 10. Sodium bicarbonate with a solution of mercuric chloride produces an effervescence and gives a white precipitate at first which changes to a brown or purple on standing, the change taking place more quickly when the mercury is in excess. Various oxychlorides of mercury are formed (M. & M., III. 217). II. Heating the alkali bicarbonates dry or in aqueous solu- tion changes them to some extent to the normal carbonates. Catechu. — i. Catechu contains a large percentage of tannic acid. [See AciDUM Tannicum.] 2. Catechu-tannic acid does not precipitate solutions of tartar emetic, but an aque- ous solution of the acid is precipitated by gelatin, albumin, and dilute sulphuric acid (U. S. D., 343). 3. Catechu-tannic acid gives a greenish-black solution or precipitate with solu- tions of ferric salts. Cerii Oxalas. — i. Cerium oxalate with alkali hydrates slowly forms the cerium hydrate and the oxalate of the alkali. 2. It dissolves in dilute hydrochloric acid or dilute sulphuric acid, and this solution is precipitated by the alkali hydrates or carbonates. Cliinoliii. — I. Chinolin turns a reddish-brown color on exposure to air. 2. It combines with acids to form salts. The salts are decomposed by fixed alkali hydrates, liberating chinolin. 3. Chinolin is precipitated by many of the alka- loidal reagents, such as iodine, picric acid, mercuric chloride, or potassium bichromate. Chloral. — i. Chloral hydrate in aqueous solution slowly undergoes decomposition, forming traces of hydrochloric acid. 2. An aqueous solution, with alkaline hydrates, alkaline car- bonates, or borax, produces chloroform and a formate of the base. 3. Chloral hydrate unites with ammonia to form chloral-ammonia (Richter, 196). Chloroform is also produced and the mixture becomes brown. 4. Mercuric oxide decom- poses chloral, forming COCl,, carbon monoxide, and carbon 6o INCOMPATIBILITIES IN PRESCRIPTIONS. dioxide (M. & M., II. 4). However, a mixture of these with- or without water, shows no apparent change for several hours. 5. Potassium permanganate oxidizes it, forming chloroform, chlorine, carbon dioxide, and oxygen (M. & M., II. 4). 6. Chloral hydrate unites with hydrocyanic acid to form chloral- hydrocyanate (Richter, 196). 7. With potassium cyanide it forms dichloracetic acid (M. & M., II. 4). If chloral hy- drate and potassium cyanide are rubbed together dry in a mortar, chemical reaction takes place with almost explosive violence, and a large amount of white fumes are given off, leaving a brown mass. If the two are powdered separately and mixed lightly, the reaction is slower, but a brown mass finally results. 8. In aqueous solution with potassium iodide chloral hydrate slowly gives chloroform and iodine (M. & M., II. 2). 9. With alcohol in the presence of water and certain soluble salts, as potassium or sodium bromide, chloral hydrate forms chlorate alcoholate, which may separate as an oily liquid. Further addition of alcohol may cause the liquids to mix. 10. Chloral hydrate in concentrated aqueous solution is a good solvent for resinous matter. It also dissolves morphine, quiniae, and other alkaloids to some extent. 1 1. A concentrated aqueous solution of chloral hydrate is said to be a good solvent for starch, and on adding iodine a cherry- red color is produced instead of the blue. Experiments made by the writer always gave the blue color. 12. Chloral hydrate when rubbed hard with acetanilid forms a slightly damp powder. It increases the solubility of acetanilid in water. [See ACETANILIDUM, No. 8.] 13. Camphor forms an un- stable liquid compound when rubbed with chloral hydrate. 14. Chloral hydrate gives a product varying from a stiff mass to a liquid when triturated dry with about an equal weight of acetamid, ammonol, borneol, monobromated camphor, car- bolic acid, diuretin, euphorin, exalgin, lead acetate, menthol, methacetin, phenacetin, pyrocatechin, salocoll, salol, so- dium phosphate, sulphonal, thymol, trional, urea, ure- thane, benzamid, or quinine sulphate. With antipyrin it INCOMPATIBILITIES IN PRESCRIPTIONS. 6l gives a damp powder, which sometimes becomes liquid and sometimes dry, seeming to depend on the condition of the atmosphere. 15. The physiological antagonists are atropine, brucine, caffeine, codeine, digitalis, physostigmine, picro- toxin, strychnine, and thebaine. Chloral Alcoliolate. — i. Chloral alcoholate is decom- posed by sulphuric acid, liberating chloral (M. & M., 11. 4). 2. It liquefies or gives a soft mass when triturated with acetamid, acetanilid, antipyrin, borneol, camphor, mono- bromated camphor, carbolic acid, diuretin, euphorin, ex- algin, menthol, methacetin, pyrocatechin, resorcin, salol, thymol, urea, or urethane. Cllloraliiiiid 1. Chloralimid is comparatively stable, not being affected by air, light, or moisture (N. D., 461). 2. It is decomposed by mineral acids, forming the corresponding ammonium salt and chloral (M. M. K., IV. 401). Chloralvini Forinaiiiidatuin. (Chloralamid.) — i. Chloral formamid is decomposed by warm water or by~ alkalies, giving chloral hydrate and ammonium formate (N. D., 461). The chloral may be further decomposed by the alkalies into chloroform and a formate. 2. It reduces silver nitrate. Chlorates. — i . Chlorates are liable to cause an explosion when triturated dry or heated with sulphur, sulphides, sul- phites, cyanides, thiosulphates, hypophosphites, nitrites, reduced iron, amorphous phosphorus, iodine, ammonium picrate, tannic acid, or subtances containing it, gallic acid, carbolic acid, oxalic acid, charcoal, sugar, honey, glycerin, starch, lycopodium, salicylic acid, shellac, and many other oxidizable substances. 2. Chlorates with sulphuric acid de- tonate or explode, forming chlorine peroxide and a perchlorate. 3. With hydrochloric acid chlorates give chlorine and oxides of chlorine. [See Chlorum.] 4. In neutral or alkaline solutions chlorates do not usually have an oxidizing effect. 5. The metallic chlorates are soluble in water and are gener- ally soluble in alcohol, except potassium. 62 INCOMPATIBILITIES IN PRESCRIPTIONS. Chloricla. [See chlorides under AciDUM Hydrochlo- RICUM.] Cliloruni. — I. Chlorine with a solution of a hydrate of a fixed alkali or an akaline earth forms a chloride and a chlo- rate. If the chlorine is added short of saturation a hypochlo- rite is formed. 2. With ammonia water chlorine gives am- monium chloride and a little nitrogen, or if the ammonia is in excess a little chlorate. If chlorine is in excess explosive nitrogen chloride may be formed, 3. With some salts of ammonium chlorine is liable to form the explosive nitrogen chloride. 4. Chlorine precipitates solutions of salts of lead, mercurous mercury, and silver as chlorides. 5. Chlorine water after standing a while is changed to hydrochloric acid. '6. Chlorine is a strong oxidizing agent, and is itself reduced to a chloride by the agents which it oxidizes. With iodides it forms iodine and then iodic acid, and in the presence of an alkali a periodate. 7. With bromides it forms bromine and in alkaline mixtures a bromate. 8. With hypophosphites phosphates are formed. 9. Sulphites or sulphides are changed to sulphates. 10. Mercurous, arsenous or ferrous compounds are changed to mercuric, arsenic, or ferric com- pounds in acid or alkaline mixtures. 11. With hydrogen dioxide oxygen is liberated. 12. Salicylic acid is changed to mono- and di-chloro-salicylic acid (M. & M., ill. 680). 13. Glycerin is converted into oxalic acid and carbon dioxide. 14. Chlorine is rapidly absorbed by alcohol. [See ALCOHOL, No. 5.] 15. Chlorine bleaches indigo, litmus, and other organic colors. 16. It oxidizes nearly all organic matter. Cliromates. [See Acidum Chromicum.] Ciiiclioiia. — I. Cinchona contains a sufficient amount of tannic acid to make its preparations incompatible with many metallic salts and other compounds. [See AciDUM Tanxicum.] 2. The tannic acid gives a color varying from brown to blackish green with solutions of ferric salts. 3. The cinchona alkaloids in solution form compounds with the gen- eral alkaloidal reagents, which compounds are nearly insol- INCOMPATIBILITIES IN PRESCRIPTIONS. 63 uble in water, but soluble in alcohol. [See Alkaloids and QUININA.] Citrates. [See Acidum Citricum.] Cocaina. — i. Cocaine is precipitated from aqueous solu- tions of its salts by the reagents that usually precipitate alka- loids. [See Alkaloids, Nos. 2 and 3.] 2. Cocaine is quite easily decomposed by strong acids, strong solutions of alkali hydrates, or by hot water, forming methyl alcohol, benzoic acid, and ecgonine. 3. Mixed with calomel in the presence of moisture cocaine hydrochloride turns the mixture gray or even black, due probably to the reduction of some of the calo- mel to metallic mercury, while at the same time some mercuric chloride is formed. The mercuric chloride then combines with the alkaloid to form a compound insoluble in water. The free alkaloid cocaine mixed with calomel does not readily darken, but may be made to do so by blowing the fumes of hydro- chloric acid over it. 4. A solution of cocaine hydrochloride is precipitated by a solution of chromic acid. 5. Alcohol, amyl nitrite, caffeine, chloral hydrate, digitalis, and mor- phine are physiologically antagonistic to cocaine. Codeiiia. — i. Codeine in aqueous solution is not pre- cipitated by alkaline carbonates, bicarbonaces, or ammonium carbonate, but is precipitated by most of the other alkaloidal reagents. [See Alkaloids, Nos, 2 and 3.] 2. Codeine in aqueous solution gives a precipitate with solutions of salts of iron, lead, copper, and some other metals (N. D.,515). This is probably due to the fact that it is quite strongly alkaline and one of the most soluble of the alkaloids. 3. With some ammonium salts, as ammonium cloride, codeine liberates am- monia. 4. If codeine is added to a solution of a morphine salt morphine is set free and usually precipitated. 5. Nitric acid gives a yellow solution with codeine. 6. Concentrated sulphuric acid with nitric acid or with ferric chloride gives a blue color with codeine (Sohn, 72). Colchicina. — i. Colchicine is darkened by exposure to light. 2. It is precipitated from aqueous solution by most of 64 INCOMPATIBILITIES IN PRESCRIPTIONS. the general alkaloidal reagents, unless the solution is quite weak. 3. Colchicine is readily decomposed by strong acids or strong solutions of alkalies, forming colchiceine, 4. Most of its salts are decomposed by water (M. & M., II. 234). 5. Nitric acid gives a blue to a violet color, turning brown and then yellow (Sohn, 42). 6. Acids generally give a yellow color. Collodiuni. — i. Collodion is gelatinized by carbolic acid (not by creosote). Alcohol renders the mass more fluid. 2. Water separates the gun-cotton. [See Pvroxvlinum.] Coiiiiiicl. — I. Coniine becomes yellow and resinoid on "keeping and gives off ammonia (U. S. D., 441). 2. It is not precipitated by the alkali hydrates or carbonates, but is by the general alkaloidal reagents, except platinic chloride. [See Alkaloids.] 3. Coniine coagulates albumin. 4. It precip- itates solutions of salts of aluminum, copper, zinc, manga- nese, iron, and silver; the precipitate with silver is soluble in excess of the alkaloid (U. S. D., 441). 5. It forms butyric acid when treated with most oxidizing agents, 6. An alco- holic solution of iodine with coniine gives a brown precipitate, which afterwards disappears, and the liquid becomes colorless (M. & M., II. 246). 7. Vapors of coniine coming in contact with those of hydrochloric acid give white fumes. Copaiba. — i . Copaiba, with the hydrates of the alkalies or alkaline earths, forms saponaceous compounds, in which the resin acts the part of an acid (U. S. D., 445). 2. With one sixteenth of its weight of magnesia which has been dampened with water, the resin of the copaiba combines slowly to form a solid mass. A similar change is produced by calcium hydrate (U. S. D., 445). Creosotvim. — i. Creosote reduces some of the inor- ganic salts, such as salts of silver, gold, and copper, to the metallic state. 2. If mixed suddenly or triturated dry with strong oxidizing agents, it is liable to cause an explosion. 3. It precipitates solutions of albumin (not gelatin or collodion) (N. D., 547). 4. Creosote with solutions of ferric salts gives INCOMPATIBILITIES IN PRESCRIPTIONS. 65 a violet-blue color, changing to greenish brown, and, unless in very dilute solution, a brown precipitate is formed. An alco- holic solution of creosote with an alcoholic solution of ferric chloride gives a bluish-green color (U. S. D,, 450). 5. Tritu- rated with silver oxide, an explosion is liable to take place. 6. With concentrated nitric acid reddish fumes of the oxides of nitrogen are given off. With dilute nitric acid a brown resin is formed (U. S. D., 450). 7. With concentrated sul- phuric acid it gives a red color, becoming black on adding more acid. 8. Creosote dissolves a large number of metallic salts and reduces some of them to the metallic condition (U. S. D., 450- Creta Pr?eparata. [See Calcium and Carbonates.] Ciipri Suli>lias. — i. Copper sulphate is precipitated by the fixed alkali hydrates as blue copper hydrate, which on standing becomes basic and black. This precipitation is more or less prevented by citrates, tartrates, salicylates, sugar, milk sugar, glycerin and other organic substances. A solution of copper sulphate and acacia is gelatinized by the alkali hydrates. 2. Ammonia water precipitates the cupric hydrate and in excess dissolves it, forming an intense blue solution. This solution dissolves cotton, filter paper, and other forms of cellu- lose. 3. Ammonfum carbonate, like ammonia water, pre- cipitates the copper and then redissolves it, forming a blue solution. 4. The carbonates of the fixed alkalies precipi- tate the copper as a basic carbonate of variable composition. 5. In neutral solutions the soluble phosphates give a blue- white precipitate of copper phosphate. 6. Arsenites in neutral solution give a green precipitate of copper arsenite. 7. Soluble iodides reduce and precipitate copper sulphate as cuprous iodide (Cu,!,), iodine being liberated. 8. In alkaline mixtures cupric compounds are reduced to cuprous oxide by arsenous acid, glucose, and many organic substances. 9. Copper sulphate coagulates a solution of albumin. 10. Tannic acid precipitates a solution of copper sulphate, and with heat reduces the copper. 11. Sodium salicylate 66 INCOMPATIBILITIES IN PRESCRIPTIONS. with copper sulphate in solution gives a green color, and the copper is not precipitated from dilute solution by alkalies. 12. -Antipyrin gives a green color to a solution of copper sulphate. Cyanida. [See Acidum Hydrocyanicum.] Decocta. — The incompatibilities of decoctions are similar to those of infusions. [See InfuSA.] Digitalis. — i. Digitalin is precipitated from solutions by tannic acid and chloride of gold, not by most of the other alkaloidal reagents (Sohn, 49). 2. With nitric acid digitalin gives at first a colorless solution, changing to yellow or green (Sohn, 50). 3. Digitonin is precipitated from aqueous solution by ammonia, tannic acid, or lead acetate (Sohn, 50). 4. All of the principles of digitalis are quite easily de- composed by strong acids or alkalies. 5. The substances that are incompatible physiologically are aconite, scoparin, strychnine, muscarine, chloral hydrate, and nitroglycerin. Diuretiii. — i. Sodio-theobromine salicylate in aqueous solution is strongly alkaline, and is decomposed by all acids, even the carbon dioxide in the air, with precipitation of theobromine (M. M. R., iv. 401). 2. Diuretin is incom- patible with bicarbonates, borates and phosphates (M. M. R., IV. 401). 3. With a solution of ferric chloride it gives a blue-violet color, due to the salicylate. 4. Diuretin forms a liquid or soft mass when rubbed with carbolic acid or chloral hydrate. With bromal hydrate, pyrocatechin, chloral alcoholate or pyrogallol it gives a stiff mass which dries. 5. It has the incompatibilities of salicylic acid and theobromine. [See AciDUM Salicylicum and THEOBRO- MINE.] Elateriiiiim. — i. Elaterin combines with the alkali hydrates to form compounds soluble in water, from which solution acids precipitate the elaterin. 2. It is precipitated from alcoholic solution by lead acetate and silver nitrate (Watts, II. 373). INCOMPATIBILITIES IN PRESCRIPTIONS. 67 Eniulsa. — Emulsions are broken up by substances which precipitate the emulsifying agent. [For emulsions made with acacia see Acacia.] Ergota. — The active principles of ergot are generally precipitated by tannic acid, potassium mercuric iodide, and some of the general alkaloidal reagents. Eucalyptol. — Eucalyptol is oxidized to cineolic acid by potassium permanganate (M. & M., 11. 526). Eug-eiiol. [See Oleum Caryophylli.] Eupliorin. (Phenyl urethane.) — i. Euphorin liquefies when triturated with antipyrin. If it is first triturated with sugar, it can then be mixed with antipyrin and dispensed as a powder (M. M. R., IV. 401). 2. It makes a liquid or soft mass when rubbed with antipyrin, borneol, bromal hydrate, camphor, monobromated camphor, carbolic acid, chloral alcoholate, chloral hydrate, exalgin, menthol, pyrocatechin, resorcin, salol, thymol or urethane. Europlieii. — i. Europhen yields iodine to metallic salts (Coblentz, 37). 2. It is decomposed by heat, light, or water, liberating iodine (N. D., 879). 4. Alkali hydrates and carbonates decompose it. 5. It should not be com- bined with starch. Exalgin. (Methyl acetanilid.) — Exalgin gives a liquid or soft mass when triturated dry with bromal hydrate, butyl chloral hydrate, carbolic acid, chloral alcoholate, chloral hydrate, euphorin, menthol, naphtol, pyrocatechin, pyro- gallol, resorcin, salicylic acid, salol, thymol or urethane. Ferropyrin. — Alkali hydrates, carbonates, or bicarbo- nates precipitate ferric hydrate from solutions of ferropyrin (Coblentz, 37). Ferri Pliosphas Solubilis. — i. The soluble phos- phate of iron, being made by mixing solutions of ferric citrate and sodium phosphate, is perhaps a mixture of ferric phos- phate and sodium citrate, or it is more probably a sodio-ferric citro-phosphate. When a dilute mineral acid other than metaphosphoric acid is added the sodium citrate or the sodio- 68 INCOMPATIBILITIES IN PRESCRIPTIONS. ferric citro-phosphate is broken up and the ferric phosphate is precipitated. Strong mineral acids may redissolve the pre- cipitate. Metaphosphoric (glacial phosphoric) acid free from orthophosphoric acid does not cause precipitation. 2. In aqueous solution the soluble phosphate of iron is precipi- tated by sodium or potassium hydrate as ferric hydrate. Ammonium hydrate gives a reddish color, but no precipitate. [See Ferricum and Acidum Phosphoricum.] Ferri Pyropliosplias SoluMlis. — i. The soluble pyrophosphate of iron is a mixture or compound similar to the soluble phosphate of iron, and on adding a dilute mineral acid the ferric pyrophosphate is thrown out of solution. Strong solutions of mineral acids may redissolve the precipi- tate. Metaphosphoric acid free from orthophosphoric acid does not cause precipitation. 2. The red-brown ferric hydrate is precipitated from aqueous solutions by potassium or sodium hydrate. 3. Ammonium hydrate turns the solu- tion red, but does not cause precipitation. [See Ferricum and pyrophosphoric acid under AciDUM PHOSPHORICUM.] Ferrosuni, — i. Ferrous salts are quite quickly changed to basic ferric compounds on being exposed to the air. Sugar, glycerin, and organic matter in general retard the oxidation. 2. Ferrous salts in aqueous solution are precipi- tated to some extent by the alkali hydrates as the white ferrous hydrate, quickly changing to the ferroso-ferric hydrate, which is of a dirty green to a black color. This precipitate ultimately oxidizes to a ferric hydrate or oxide. Ammonium chloride or sulphate, soluble citrates or tartrates, sugar, glycerin and many organic compounds, dissolve the ferrous hydrate or prevent the precipitation. 3. The soluble carbon- ates precipitate the ferrous carbonate, white if purely ferrous, but quickly becoming green and ultimately brown, due to the formation of a ferric compound. 4. The soluble phosphates precipitate the white or bluish-white ferrous phosphate. 5. With nearly neutral solutions borax gives a white pre- cipitate. 6. The soluble sulphides (not hydrogen sulphide) INCOMPATIBILITIES IN PRESCRIPTIONS. 69 precipitate the black ferrous sulphide. 7. Ferrocyanides precipitate the light blue ferrous ferrocyanide. 8. Ferricy- anides precipitate the dark blue ferrous ferricyanide. 9. Tan- nic acid with strong solutions of ferrous salts precipitates the white gelatinous ferrous tannate. This quickly oxidizes, forming the nearly black ferric tannate. Ferrous salts usually contain enough of a ferric salt to give the dark color at once. 10. Gallic acid with a concentrated solution of a ferrous salt gives a white precipitate which soon turns dark, due to the oxidation of the iron and formation of the ferric gallate. 1 1. Ferrous salts in solution are oxidized to ferric compounds by salts of gold or silver, by hydrogen dioxide, chromates, permanganates, nitrous or nitric acid, chlorine or chlorates in acid solution, bromine or bromates in acid solution, iodates in acid mixture, mercuric compounds in alkaline mix- ture, arsenates in alkaline mixtures, and by oxygen of the air. 12. The alkaline citrates in solution modify the astrin- gent effects of ferrous salts, and dissolve many of the salts not soluble in water. Ferricuiu. — i. Ferric salts are precipitated from their aqueous solutions by the alkali hydrates and carbonates as the red-brown ferric hydrate. This precipitation is more or less prevented by the presence of sugar, glycerin, citrates, tartrates, and other organic compounds. 2. When the in- soluble carbonates of barium, calcium, magnesium, and cop- per are added to solutions of ferric salts the ferric hydrate is precipitated, the base added combining with the acid of the ferric salt. 3. Borax with solutions of ferric salts gives an insoluble basic borate (Watts, I. 530). Sugar, glycerin, citrates, and tartrates prevent or retard precipitation. 4. Solutions of the alkali phosphates precipitate from neutral solutions of ferric salts the white ferric phosphate, the pre- cipitation being prevented by citrates, tartrates, and consid- erable excess of free acids. 5. The alkali sulphides precipi- tate the black ferrous sulphide after reducing the ferric compound to ferrous and liberating sulphur. Hydrogen 70 INCOMPATIBILITIES IN PRESCRIPTIONS. sulphide reduces ferric to ferrous and liberates sulphur but causes no precipitation of iron. 6. Soluble cyanides pre- cipitate the neutral solutions of ferric salts as ferric hydrate with evolution of hydrocyanic acid. 7. Ferrocyanides with ferric salts give the blue precipitate of ferric ferrocyanide (Prussian blue) ; this is prevented to some extent by citrates in neutral solutions. 8. Ferricyanides give a brown solu- tion with ferric salts. 9. With solutions of ferric salts sul- phites give a red solution of ferric sulphite, which changes on heating or standing to ferrous sulphate and the solution becomes nearly colorless. 10. Phosphoric acid in excess decolorizes a solution of ferric chloride by forming the color- less terric phosphate. ii. In neutral solutions the alkali hypophosphites precipitate ferric salts as ferric hypophos- phite, but in acid solutions the iron is reduced to the ferrous condition and the hypophosphite is oxidized to a phosphate. 12. Hydriodic acid and soluble iodides with a mineral acid reduce ferric compounds to ferrous, iodine being liberated and precipitated if the iodide is entirely decomposed. 13. Arsenites give precipitates of basic ferric arsenite with solu- tions of ferric salts if they are not too strongly acid. The basic ferric arsenite is changed to some extent to a ferrous arsenate (P. & J., 118). 14. The of^cial tannic acid gives a blue-black solution or precipitate of ferric tannate. Phos- phoric acid in excess destroys the color by breaking up the compound and forming the colorless ferric phosphate. Some tannic acids give a green-black color. With the exception of gentian, quassia, columbo, American columbo, chiretta, and canella nearly all drugs contain tannin. 15. Gallic acid gives a blue-black color with a solution of ferric chloride. [See AciDUM Gallicum, No. 7.] 16. Acetates give a deep dull red liquid with nearly neutral solutions of ferric salts, due to the formation of ferric acetate. This solution on heating throws down a precipitate of basic ferric acetate. Acetic acid does not increase the color of a solution of ferric chloride unless the iron solution is quite highly diluted. 17. Soluble INCOMPATIBILITIES IN PRESCRIPTIONS. 71 benzoates precipitate nearly neutral solutions of ferric salts as ferric benzoate which is flesh-colored. The presence of an excess of free acid or of alkali tartrate interferes or prevents the precipitation. 18. With solutions of the salicylates fer- ric salts give a blue-violet to violet-red solution ; the color is destroyed by a large excess of a mineral acid. In concen- trated or neutral solutions ferric salicylate may be precipi- tated. 19. Carbolic acid with concentrated solutions of ferric chloride gives but little increase in color. On diluting with water the solution becomes green and more water changes it to violet blue. 20. In dilute aqueous solutions creosote or guaiacol gives with ferric chloride a violet-blue color which soon changes to green brown. An alcoholic solution of ferric chloride with creosote gives blue green. 21. Acetanilid with an alcoholic solution of ferric chloride gives a red color. With an aqueous solution it gives no color unless heated, and then the color fades on cooling. If the solution is heated for several minutes the color is changed to a permanent green. 22. Antipyrin gives a red color with a solution of a ferric salt. [See Antipyrinum, No. 3.] 23. Phenacetin with a tincture of ferric chloride gives a deep red solution. 24. With pyrocatechin a solution of ferric chloride gives a green color; 25. with pyrogallol it gives a red; 26. and with resorcin, a violet. 27. An alcoholic solu- tion of salol gives a violet color with a tincture of iron, but when sufficient water is added the color is destroyed and the salol precipitated. 28. Oil of wintergreen gives a violet color with an alcoholic solution of ferric chloride; 29. oils of cloves, bay, and pimenta give a blue to a green ; 30. oil of cinnamon gives a brown; 31. oil of thyme gives a green brown, changing to red. 32. An alcoholic solution of ferric chloride gives a dark brown-green color with podophyllin; 33. with aloin it gives a green black to a brown black; 34. Avith benzoin, a brown to green; 35. with gamboge, a black brown; 36. with asafoetida or storax, a green brown; 27' with myrrh, a red brown; 38. with guaiac, a blue to brown; 'J 2. INCOMPATIBILITIES IN PRESCRIPTIONS. 39. with balsam of Peru, a green black ; 40, with balsam of Tolu, a brown; 41. and with shellac, a black. 42. With a nearly neutral aqueous solution of ferric chloride morphine gives a blue to green solution, and with apomorphine it gives a red changing to a black. 43. Solutions of ferric salts gela- tinize mucilage of acacia. [See Acacia, No. 2.] 44, They coagulate solutions of albumin. Ferruin Reductuin. — i. Reduced iron combines with acids to form salts. 2. It is oxidized by moist air. 3. In the presence of water it reduce's to the metallic condition salts of copper, bismuth, lead, silver, mercury, and antimony. 4. Triturated dry with strong oxidizing agents, such as potas- sium permanganate or potassium chlorate, it is liable to cause an explosion. 5. In the presence of water iron forms ferrous iodide with iodine, and ferrous bromide with bromine. 6. Iron is slowly oxidized to a hydrate by hydrogen dioxide water. rormaldeliydiini. (Formalin). — i. Formic aldehyde in solution slowly deposits the solid crystalline paraformalde- hyde which is a condensation product, consisting of three molecules of formaldehyde and which is decomposed by high heat changing back to formaldehyde. 2. Formic aldehyde with dilute solutions of the hydrates of the fixed alkalies and alkaline earths is converted into methylenenitan and for- mose (Richter, 192). Alkalies convert formaldehyde into methyl alcohol and a formate of the base (Wade, 73). For- maldehyde neutralizes alkalies but does not form true salts (W. D., XXI. 109). 3. Ammonia unites to form hexameth}-- leneamine (Richter, 192). 4. Hydrogen sulphide precipi- tates it as trithiomethylene (Richter, 192). 5. Hydrogen dioxide water oxidizes formic aldehyde to formic acid. 6. Formaldehyde is a strong reducing agent, reducing salts of gold and alkaline solutions of salts of silver and copper. 7. It coagulates solutions of gelatin and renders the gelatin in- soluble in water or alkalies. 8. With alkaline bisulphites it is said to be incompatible (M, M. R., iv. 401). INCOMPATIBILITIES IN PRESCRIPTIONS. 7S Galla. [See AciDUM Tannicum.] Gallates. [See Acidum Gallicum.] Gelatiniim. — i. Solutions of gelatin are coagulated by tannic acid, picric acid, metaphosphoric acid, chlorine water, mercuric chloride, platinum chloride, alumnol, alcohol, or formaldehyde. Aqueous solutions are not pre- cipitated by alum, lead acetate, ferric chloride, dilute acids, or dilute alkalies. 2. Heating an aqueous solution of gelatin for some time renders it incapable of gelatinizing. Gloiioiiiuin. — I. Nitroglycerin explodes violently on percussion. 2. When impure it gradually decomposes, form- ing glyceric, oxalic, and nitrous acids and the gases formed may burst the container (M. & M., II. 619). 3. Alkalies or their carbonates decompose it when dissolved in alcohol, forming a nitrite, nitrate, acetate, oxalate, and formate (M. & M., II. 619). Alkalies convert it into glycerin and a nitrate of the base (Richter, 454). Glucosides. — i. Glucosides are decomposed by pro- longed contact with mineral acids, alkalies, hot water, or ferments. Some glucosides may be decomposed by one of these agents, others by two or more of them. One of the products formed is glucose. 2. Tannic acid or lead subacetate generally precipitates the glucosides from their aqueous solutions. 3. The glucosides are not usually pre- cipitated by the alkali hydrates or carbonates or by many of the general alkaloidal reagents. 4. Many of them give color reactions resembling those produced by the alkaloids. Glycerinuiii. — i. Glycerin with borax forms glycerol borate and sodium metaborate. The glycerol borate is de- composed by water, forming boric acid and glycerin. In consequence of the formation of free acid, this mixture is incompatible with carbonates, but generally compatible with solutions of alkaloidal salts where borax alone would cause a precipitation. Glucose, honey, and some other organic com- pounds act like glycerin. 2. Strong nitric acid mixed with concentrated sulphuric acid converts glycerin into the explo- 74 INCOMPATIBILITIES IN PRESCRIPTIONS. sive nitroglycerin. When glycerin is carefully treated with nitric acid, it is converted into a mixture of oxalic acid, glyceric acid, and other organic acids (Allen, II. 278). Warming glycerin with dilute nitric acid may cause a violent reaction. 3. Gently heated with solid potassium hydrate glycerin is converted into potassium acetate and formate (Allen, II. 278). 4. In dilute solutions potassium permanga- nate changes glycerin to formic, propionic, and tartronic acids (M. & M., II. 618). In a strongly alkaline solution oxalic acid and carbon dioxide are formed (Allen, II. 278). Manganese dioxide is precipitated. 5. Oxidizing agents, as chromates, chlorinated lime, nitrohydrochloric acid, hydrogen dioxide, or manganese dioxide with hydro- chloric acid, convert glycerin into oxalic acid and carbon dioxide. When glycerin is rubbed with the dry oxidizing agents explosion is liable to take place. 6. Concentrated sulphuric acid with glycerin forms acrolein. 7. Glycerin may be made to combine with several organic and inorganic acids (U. S. D., 654). 8. Glycerin dissolves alkalies, alkaline earths, and many metallic oxides, forming in all probability compounds similar to alcoholates (Richter, 453). 9. Glycerin prevents to some extent the precipita- tion, by alkali hydrates and carbonates, of solutions of salts of lead, copper, antimony, aluminum, chromium, iron, zinc, and magnesium. 10. It dissolves most deliquescent salts and increases the solubility of many inorganic and organic salts, ii. Glycerin sometimes precipitates alkaloi- dal salts from their aqueous or acidulated solutions (U. S. D., 653). 12. With most fixed oils it does not mix to form clear solutions. 13. Glycerin is sometimes contami- nated with iron from the container, and this may give a color with carbolic acid, tannic acid, and other sub- stances. Glyeeritviin Boroglycerini. — Glycerite of borogly- cerin is decomposed by water and the boric acid liberated may be precipitated. INCOMPATIBILITIES IN PRESCRIPTIONS. 75 Glycyrrhiziiiuiii Aiiimoniatum. — i. Ammoniated ■glycyrrhizin in aqueous solution is decomposed and the glycyrrhizic acid precipitated by mineral acids ; the taste is changed from sweet to somewhat bitter, 2. With solutions of salts of many of the heavy metals it gives voluminous precipitates (N. D., 789). 3. Fixed alkalies liberate am- monia from it. Gviaiaci Resina. — i. An alcoholic solution of the fresh resin of guaiac is colored blue by nitric acid, chromic acid, chlorine, potassium ferricyanide, potassium per- manganate, ferric chloride, g^old chloride, ozone, spirit of nitrous ether, and other oxidizing agents. This is due to the action on the guaiaconic acid. With an excess of the oxidizing agent the color is changed to green and then red. Continued exposure to light or heat deprives the guaiac of the property of being colored blue by oxidizing agents. 2. Both the resin and the tincture turn green in the light. 3. Sulphuric acid dissolves it, forming a red solution with a tinge of blue. 4. Either in substance or in tincture, guaiac gives a blue color with mucilage of acacia. Giiaiacoluni. — i. The incompatibilities of guaiacol are similar to creosote. [See Creosotum.] 2. It combines with some acids to form crystalline compounds. 3. With ferric chloride it gives at first a blue color, changing to green on adding more ferric chloride. 4. It reduces a few salts, a^ gold chloride and silver nitrate, to the metallic condition, Homatropina. — The incompatibilities are similar to atropine. [See Atropina.] Hydrargyri Cliloricluni Corrosivum. — i. Mer- curic chloride in aqueous solution is precipitated by solutions of fixed alkali hydrates or lime water. The precipitate is the orange-yellow mercuric oxide if the hydrate is in excess, or if the mercuric salt is in excess it will be the red- brown basic chloride of mercury. The precipitation is pre- vented to some extent by the presence of citrates, tartrates, glycerin, sugar, and acacia although there may form a steel- 76 INCOMPATIBILITIES IN PRESCRIPTIONS. gray precipitate in a few days. 2. Ammonium hydrate gives the "white precipitate," or " ammoniated mercury," the nitrogen dihydrogen mercuric chloride. 3. Ammonium carbonate acts like ammonium hydrate. 4. Potassium carbonate or sodium carbonate precipitates solutions of mercuric chloride as the red-brown oxychloride, which by excess of the carbonate with heat is converted into the yellow mercuric oxide. Citrates, tartrates, glycerin, acacia, and sugar prevent the precipitation to some extent. 5. A solu- tion of mercuric chloride with sodium or potassium bicar- bonate gives an effervescence and a white precipitate. If the mercuric salt is in excess the precipitate turns to a purplish red in a few hours. If the bicarbonate is in excess the precipitate remains white for some time but may ulti- mately change to the purplish red. Various oxychlorides are formed (M. & M., in. 217). 6. Borax precipitates the red- brown basic mercuric chloride (Watts, I. 641). 7. Hydrogen sulphide and the alkali sulphides with solutions of mercuric chloride give mercuric sulphide. The precipitate first formed is white and consists of the union of mercuric chloride and mercuric sulphide ; by further addition of the precipitating agent the black mercuric sulphide is formed (P. & J., 1 10). S. The soluble iodides precipitate solutions of mercuric chloride as mercuric iodide, first reddish yellow, becoming red. This precipitate dissolves in excess of the soluble iodide or excess of mercuric chloride, forming double compounds. If potas- sium idodide has been used in excess, the double compound is approximately represented by the formula (KI)jHglj. A solution of this double salt is known as " Mayer's reagent" and precipitates nearly all alkaloids from solutions of their salts; the presence of alcohol prevents this precipitation to some extent. 9. The soluble bromides precipitate from concentrated solutions of mercuric salts the white mercuric bromide, which is soluble in excess of the soluble bromide or in excess of the mercuric salt (P. & J., no). Ordinarily no trouble is experienced in combining these. 10. Soluble INCOMPATIBILITIES IN PRESCRIPTIONS. -jy phosphates precipitate from neutral solutions of mercuric chloride the white mercuric phosphate. 1 1 . Mercuric chloride combines with the chlorides of the alkalies to form double compounds. 12. Hypophosphorous acid and hypophos- phites reduce mercuric chloride to mercurous chloride and finally to metallic mercury. 13. Sulphurous acid and soluble sulphites reduce mercuric chloride to mercurous chloride. 14. Thiosulphates added to a solution of mer- curic chloride give a white precipitate, then yellow, then black. The black precipitate is sulphide of mercury. 15. Mercuric chloride is reduced by metallic copper, zinc, or iron, in the presence of water, to calomel, and then metallic mercury. 16. Arsenites in alkaline mixtures reduce mer- curic chloride to calomel and then metallic mercury, and are changed to arsenates. 17. Tartar emetic reduces corrosive sublimate and precipitates it as calomel; in alkaline mixtures metallic mercury is formed. 18. Ferrous compounds in alkaline mixtures with mercuric compounds are oxidized to ferric compounds, and reduce mercuric to mercurous. 19. If an aqueous solution of mercuric chloride is exposed to light, hydrochloric acid is gradually liberated and calomel precip- itated (N. D., 821). 20. Alcohol slowly reduces mercuric chloride to calomel (M. & M,, I. 98). 21. According to some writers corrosive sublimate is slowly reduced to calomel by compound syrup of sarsaparilla and by honey but not by pure syrup; the precipitation is retarded by sodium chloride (U. S. D., 689). 22. A solution of albumin is coagulated by mercuric chloride ; this is prevented by the presence of sodium or ammonium chloride 23. Mercuric chloride precipitates from concentrated aqueous solutions nearly all alkaloidal salts, some neutral and bitter prin- ciples, some glucosides, antipyrin, tannic acid, vegetable extractive matter, and gelatin. Hydrargyri Cliloriduiu Mite. — i. Calomel is changed to the black mercurous oxide by a solution of the hydrates of potassium, sodium, calcium, or barium. 2. Solutions of 78 INCOMPATIBILITIES IN PRESCRIPTIONS. the carbonates of the fixed alkalies convert calomel into a black mass, which is probably a mixture of the basic carbon- ate and oxide. 3. Calomel with ammonia water forms the black compound, nitrogen dihydrogen dimercurous chlo- ride. 4. Ammonium carbonate acts like ammonia water. 5. The soluble iodides in the presence of water convert calomel into yellow mercurous iodide, which is further decomposed by an excess of the soluble iodide, form- ing metallic mercury and mercuric iodide. This mercuric iodide combines with the soluble iodide to form a double compound which is soluble in water. The presence of a little metallic mercury gives a green color with mercurous iodide. The color becomes more gray or black as the proportion of metallic mercury increases and the mercurous iodide decreases. 6. Soluble bromides act similarly to soluble iodides. 7. Accord- ing to M. Mialhe, calomel is in part converted into corrosive sublimate and metallic mercury by ammonium, potassium, or sodium chloride at the temperature of the body (U. S. D., 695). A number of other experimenters call attention to the decomposition. (See Watts, III. 896. D. C, XLIII. 176. Proceedings Kansas Pharm. Assoc, for 1897.) The change seems to be more marked in the presence of gastric juice or pancreatin. O. H. Tansy (in Pharm. Rundschau) has made experiments to prove the fallacy of the belief that sodium chloride and calomel are incompatible. Diekman (in Ph. Era, XXII. 7) made experiments showing that the amount of mer- curic chloride formed in the test tube is not over six tenths per cent, of the calomel taken, and consequently not enough to explain the increased action which the mixture sometimes seems to have Prof. Pouchet claims that if sodium chloride is capable of converting calomel then it will be necessary to eliminate all of the sodium chloride in the system before giving a dose of calomel. Numerous other experimenters lend their support to the belief that no change, or but very little, takes place, and some bring forward clinical results to prove their point. One writer says that the exaggeration of INCOMPATIBILITIES IN PRESCRIPTIONS. 79 the toxic effect of calomel, after ingestion of salt or organic acids, arises from the fact that its combination with albu- minoid substances in the stomach is facilitated and will yield products much more soluble, so that calomel will be absorbed in larger amounts. 8. Hydrocyanic acid and soluble cyanides in aqueous solution convert calomel into metal- lic mercury and mercuric cyanide and chloride. 9. Bicar- bonate of sodium with calomel produces corrosive sublimate very slowly ; the change does not take place within four to six weeks ordinarily (Scoville, 229). Whether any change takes place or not, calomel is more frequently given with sodium bicarbonate than without it. 10. Calomel with alkali sulphites in solution separates metallic mercury, and a double sulphite of the alkali and mercury goes into solution (M. & M., III. 216). II. Solutions of hydrogen sulphide or alkali sulphides convert calomel into the black mercurous sulphide. 12. Iodine changes calomel into mercuric chlo- ride and mercuric iodide in the presence of water or alcohol. 13. A mixture of iodoform and calomel exposed to light gives red mercuric iodide and the odor of iodoform is lost. 14. Exposed to sunlight calomel darkens, due to the separa- tion of metallic mercury ; mercuric chloride is also formed. 15. Calomel is said to be changed to metallic mercury and mercuric chloride by heavy trituration. 16. Boiling hydro- chloric acid converts calomel into mercuric chloride and metallic mercury; if dilute hydrochloric acid is used, no metallic mercury will be separated (M. & M., ill. 216). 17. Calomel is reduced to metallic mercury by nitrous acid, spirit of nitrous ether, hypophosphorous acid, and in alka- line mixtures by arsenites and tartar emetic. 18. Mer- curous chloride is oxidized to mercuric compounds by nitric and nitrohydrochloric acids, chlorine, bromine, iodine, hydrogen dioxide, and in alkaline mixtures by silver salts. 19. Soap is generally alkaline and darkens calomel, probably forming an oxide. 20. Calomel in the presence of moisture is darkened by certain alkaloids, such as cocaine or pilocar- 8o INCOMPATIBILITIES IN PRESCRIPTIONS. pine. The darkening is due to the formation of metallic mer- cury, while at the same time some mercuric chloride is formed, which combines with the alkaloid. 21. Calomel is slowly turned dark in the presence of moisture by antipyrin, but at once when sodium bicarbonate is mixed with it. Metallic mercury and a mercuric compound is formed. 22. Calomel is said to be changed to metallic mercury and mercuric chlo- ride by cane-sugar even in the absence of moisture. Con- siderable time is required for the change. Milk-sugar gives the reaction more quickly. Acacia and tragacanth have similar properties but in a lesser degree. Hydrargyri Cyaiiiduni. — Mercuric cyanide, so far as the base is concerned, has incompatibilities similar to mer- curic chloride, except that aqueous solutions are not precipi- tated by alkali hydrates or iodides on account of the formation of soluble double compounds. [See Hydrargyri Chlori- DUM Corrosivum and AciDUM Hydrocyanicum.] Hydrargyri lodiduni Flavum. — i. Mercurous iodide is rapidly darkened by the light, particularly in the presence of moisture. The darkening is in proportion to the decom- position into mercuric iodide and mercury. 2. With solutions of iodides mercurous iodide is decomposed, forming mer- curic iodide and mercury. [See Hydrargyri Chloridum Mite, No. 5.] 3. Mercurous iodide is reduced and oxidized by the same reagents that reduce and oxidize calomel. Hydrargyri lodidum Rulbriini. — i. Mercuric iodide is decomposed by solutions of fixed alkali hydrates, form- ing the yellow mercuric oxide and a soluble double iodide of the alkali and mercury. 2. Lime, sodium carbonate, and potassium carbonate do not decompose mercuric iodide in the presence of water, but do in the presence of alcohol (M. & M., III. 220). 3. With soluble iodides it forms solu- ble double compounds. 4. The incompatibilities are quite similar to those of mercuric chloride. 5. A solution of sodium thiosulphate dissolves mercuric iodide. Hydrargyri Oxiduni Flaviiin. — i. Mercuric oxide INCOMPATIBILITIES IN PRESCRIPTIONS. 8 1 -combines with most acids to form salts. 2. With mercuric chloride in solution it forms the red-brown oxychloride. 3. Mercuric oxide darkens in the light, forming mercury and oxygen (M, & M., ill. 222). 4. Mercuric oxide precipitates bases from solutions of their chlorides but not from oxysalts (M. & M., III. 909). Hydrargyri Subsvilphas Flaviis. — i. Turpeth min- eral dissolves readily in sulphuric, nitric, or hydrochloric acid. 2. Solutions of fixed alkali hydrates decompose tur- peth mineral, forming mercuric oxide and the sulphate of the alkali. Hydrargyriiin Ainiiioniatuin. — i. White precipitate is decomposed by solutions of the fixed alkali hydrates or lime water, liberating ammonia and forming the yellow mercuroxy-ammonium chloride (M. & M., III. 208). 2. Water decomposes it slowly, forming mercuroxy-ammonium chlo- ride and ammonium chloride (M. &. M., III. 208). 3. When ammoniated mercury is triturated with iodine, the mixture will pufT up after a time from the spontaneous decomposition of nitrogen iodide formed in it ; but in the presence of alco- hol the decomposition takes place suddenly and with violent explosion (N, D., 847). 4. Bromine or chlorine causes the evolution of hydrogen and the formation of mercuric bromide or mercuric chloride (M. & M., III. 208). 5, Ammoniated mercury is dissolved by a solution of sodium thiosulphate in the cold, evolving ammonia; if heat is applied mercuric sulphide is formed (N, D,, 846). Hydrates, Fixed Alkali. — i. The fixed alkali hydrates are the hydrates of sodium and potassium. In aqueous solu- tion they combine with acids to form salts. 2. Exposed to the air they absorb carbon dioxide. 3. In the presence of water and heat they liberate ammonium from its compounds. 4. They precipitate solutions of salts of all other common metals and the precipitate is a hydrate, except in case of silver, mercury, and antimony, in which cases it is an oxide. The precipitation is prevented or hindered with salts of %%^G 82 INCOMPATIBILITIES IN PRESCRIPTIONS. mercury, lead, copper, antimony, aluminum, chromium, iron, zinc, and calcium, by the presence of sugar, glycerin, acacia, citrates, tartrates, and other organic matter. 5. Calo- mel is turned black, due to the formation of mercurous oxide. 6. Gallic acid combines with the hydrates, forming com- pounds that vary in color from a green to a yellow or brown. [See AciDUM Gallicum, Nos, i and 2.] 7. Tannic acid combines with the hydrates, giving various colors on stand- ing. .[See AciDUM Tannicum, No. 2.] 8. Potassium hydrate with a concentrated solution of tartaric acid gives a precipitate of cream of tartar. 9. Chloral hydrate is decom- posed by the alkali hydrates, giving chloroform and a formate of the base. 10. The alkali hydrates precipitate nearly all of the alkaloids from aqueous solution of their salts, the precipitate being the free alkaloid. In some cases the pre- cipitate is soluble in excess of the hydrate. The precipita- tion is sometimes prevented by alcohol which is a solvent, for the alkaloids, ii. They decompose some of the alka- loids, such as atropine, hyoscyamine, cocaine, and aconitine, when left in contact for some time, or more quickly when heated. 12. Alkali hydrates decompose many of the gluco- sides when warmed with them. 13. They dissolve some principles, as santonin and cantharidin. 14. With fats and fixed oils they form glycerin and a salt (soap) of the fat acid. 15. With resins they form resin soaps. 16. They decompose some substances like salol and oil of wintergreen. [See Alkalies.] Hydrate, Volatile Alkali. — Ammonium hydrate is the only common volatile alkali. i. Ammonia combines with acids to form salts. 2. It precipitates solutions of salts of lead, silver, mercury, bismuth, tin, antimony, copper, cadmium, iron, aluminum, chromium, cobalt, nickel, man- ganese, and zinc. The precipitate is a hydrate, except in case of silver and antimony, when it is an oxide ; in case of lead, it is a basic salt ; in case of mercurous salts, the precipi- tate is a black double compound ; and in case of mercuric INCOMPATIBILITIES IN PRESCRIPTIONS. 83 salts, the precipitate is a white double compound. The pre- cipitation many times is prevented or hindered by sugar, glycerin, acacia, citrates, tartrates, andiOther organic matter. 3. A solution of corrosive sublimate is precipitated by ammo- nia, giving ammoniated mercury (NH^HgCl). 4. Calomel is converted into a black compound, nitrogen dihydrogen dimer- curous chloride (NHjHg.Cl). 5. With chlorine ammonia forms ammonium chloride and nitrogen. If a larger pro- portion of chlorine gas is used, the ammonium chloride may be decomposed, forming hydrochloric acid and nitrogen. If a still larger proportion of chlorine gas is used, the ammo- nium chloride may be decomposed into hydrochloric acid and explosive nitrogen chloride (P. & J., 24). 6. Bromine acts somewhat like chlorine. 7. With iodine ammonium hydrate may under certain circumstances form ammonium iodide, ammonium iodate, and water; under different circumstances ammonium iodide and the explosive iodide of nitrogen are formed (P. & J., 24). [See lODUM, No. 2.] 8. Permanga- nates oxidize ammonium hydrate to a nitrate. 9. With carbolic acid ammonia gives at first a colorless solution, which slowly becomes green, then deep blue, and finally purplish blue. 10. With carbolic acid and sodium hypo- chlorite ammonia produces a deep blue color. 11. With a concentrated solution of tartaric acid ammonia gives a pre- cipitate of ammonium bitartrate. 12. In concentrated solu- tions of picric acid ammonia gives a precipitate. 13. Gallic acid gives a yellow to a red-brown color with ammonia water. 14. Chloral hydrate is decomposed, giving chloroform and a formate of ammonium or chloral-ammonia. 15. Ammonia added to an alcoholic solution of thymol slowly gives a green color. 16. It precipitates nearly all alkaloids from aqueous solutions of their salts. The precipitate is the free alkaloid, and is sometimes soluble in a large excess of ammonia. [See Alkalies.] Hydrogenii Dioxidum. [See Aqua Hydrogenii DiOXIDI.] •84 INCOMPATIBILITIES IN PRESCRIPTIONS. Hyclroqviiiione. — i. Hydroquinone is oxidized to qui- none by ferric chloride, chlorine, dilute nitric acid, and chromic acid (M, & M., ii. 730). 2. Strong nitric acid oxi- dizes it to oxalic acid (M. & M., 11. 730). 3. An aqueous solution turns brown in the air, more quickly in the presence of an alkali. 4. A strong aqueous solution is precipitated by ferric chloride, soluble in excess of the latter (M. & M., II. 730). Hyoscyaniiiia. — i. Hyoscyamine is converted into atro- pine by heating to 248° F., or above its melting point, for five or six hours. 2. It is not precipitated by bicarbon- ates or ammonium carbonate, except from concentrated solutions. 3. It is easily decomposed by warming with alkalies or water. 4. It has about the same incompatibili- ties as atropine. [See Atropina.] Hyoscyamvis. [See Atropina.] Hypochlorites. — i. The more common hypochlorites are found in the form of chlorinated lime, solution of chlori- nated soda, and solution of chlorinated potassa. 2. Hypo- chlorites are decomposed by all acids at the ordinary tem- perature with liberation of chlorine. Consequently hypo- chlorites are strong oxidizing agents and have in general the same effect as chlorine. [See Chlorum.] 3. The hypo- chlorites are soluble in water, but insoluble in alcohol. 4. Care should be used in mixing hypochlorites with readily oxidizable substances to avoid explosion or violent reaction. 5. They bleach vegetable colors. [See Calx Chlorata.] Hypophosphites. [See Acidum Hypophosphoro- ^SUM.] Hyposulphites. [See SODii Thiosulphas.] Ichthyol. — I. Acids combine with the ammonia and precipitate the ichthyolsulphonic acid as a dark resinous mass which adheres to the sides of the vessel. 2. Alkaline hydrates or carbonates liberate ammonia. 3. Ferric salts in solution with ichthyol form compounds of iron and ichthyol, while at the same time a partial oxidation of ichthyol is INCOMPATIBILITIES IN PRESCRIPTIONS. 85 larought about by the ferric salt. Ferrous salts precipitate the sulpho-ichthyolate of iron (Am. D., XXVII, 364). 4. Potassium mercuric iodide precipitates it. 5. It is slowly precipitated by mercuric chloride. 6. Ichthyol precipitates alkaloids from solutions of their salts, forming a sticky resin- ous mass. 7. It is soluble in water, only partially soluble in alcohol or ether, but soluble in a mixture of the last two. Iiifusa. — I. Infusions generally contain some tannic acid, albuminous and extractive matters, which are precipi- tated by many of the metallic salts, such as mercuric chlo- ride, lead acetate, silver nitrate, tartar emetic, or ferric chloride. 2. When the tannic acid is present in considerable amount, infusions are incompatible with alkaloidal salts, because of the formation of the insoluble alkaloidal tannate. 3. Many of the infusions are decolorized by a solution of lead subacetate or by aluminum hydrate. 4. Infusions should not be mixed with alcoholic solutions of substances insoluble in water. lodates. — i. lodates sometimes occur as impurities in iodides, and in such cases they liberate iodine when brought in contact with acids. 2. lodates in solution with a dilute mineral acid are reduced to iodine by hypophosphites, iodides, bromides, nitrites, arsenous acid, ferrous com- pounds, and morphine. loclida. [See Acidum Hydriodicum.] locloforuin. — i. Iodoform heated with a solution of an alkali hydrate gives an iodide and a formate. 2. Silver nitrate in solution decomposes iodoform, producing silver iodide, nitric acid, and carbon monoxide (M. & M., III. 33). Triturated dry with silver nitrate, violent reaction takes place with the formation of silver iodide, carbon dioxide, and nitrogen tetroxide (Ph. E., viii. 302). 3. The color of a mixture of calomel and iodoform is yellow, but when it is -exposed to light the color changes to red, due to the forma- tion of the red iodide of mercury. Perhaps some chloroform is also produced. 4. When gently heated with yellow mer- 86 INCOMPATIBILITIES IN PRESCRIPTIONS. curie oxide iodoform is decomposed, giving carbon monox- ide, formic acid, mercuric iodide, and water (M. & M., ill, 33). 5. Exposed to direct sunlight, iodoform is completely^ oxidized by the air, forming carbon dioxide, iodine, and water (M, & M., in. 33). 6. Iodoform in solution or mixed with a fatty substance decomposes in the light, forming iodine and methyl iodide (M. & M., Ill, 33). For a time the iodine will be taken up by the fatty matter (unless it is petrolatum), forming colorless addition products (M. M. R., IX. 1 14). 7. Iodoform with hydrogen dioxide water seems not to be readily affected, but when in solution with ether hydrogen dioxide liberates iodine. 8. Tannin slowly deodor- izes and decomposes iodoform. 9. Balsam of Peru deodor- izes it and forms a compound with it (U. S. D., 741). lodol. — lodol remains unchanged when heated below 100 C. (N. D., 879). lodoplienacetiii. (lodophinin.) — i. Water decomposes iodophenacetin, liberating iodine (M, M. R., IV. 359). 2. Alka- lies abstract iodine, regenerating phenacetin (M. M. R., IV. 359). 3. It should not be mixed with substances having a strong affinity for iodine. loduiii. — I. In aqueous solution fixed alkali hydrates or carbonates decolorize iodine, forming soluble iodides and iodates. 2. Iodine with ammonia water slowly becomes colorless, forming chiefly ammonium iodide, with some ammonium iodate. There is a liability of there being precipitated a dark-brown powder, the "iodide of nitrogen," which when dry is easily and violently explosive. Explosive compounds of nitrogen and iodine may also be formed by mixing alcoholic solutions of am- monia and iodine; by adding a solution of chlorinated lime (neutralized by acetic acid) to an aqueous solution of ammo- nium iodide; by adding ammonia to a mixture of hydro- chloric acid and iodic acid; by the action of nitrogen chloride on an aqueous solution of potassium iodide; or by adding an alcoholic solution of iodine to ammoniated mer- INCOMPATIBILITIES IN PRESCRIPTIONS. 87 cury. Analyses of the products of these reactions seem to show that at least three different explosive compounds are formed, differing in the number of hydrogen atoms replaced by the iodine (M. & M., iii. 560). 3. Nitric acid slowly oxidizes iodine to iodic acid. 4. Hypophosphites are •changed to phosphates, and the iodine is reduced to an iodide. 5. Hydrogen sulphide forms hydriodic acid and sulphur. 6. Thiosulphates form sulphates and an iodide. 7. Sulphites form sulphates and an iodide. 8. Chlorine forms iodic and hydrochloric acids, and in the presence of potassium hydroxide a periodate. 9. Chlorates in the pres- ence of an acid form chlorides and iodic acid. 10. Bromine in the presence of an alkali hydroxide forms a bromide and an iodate. 11. Iodine changes mercurous compounds either in acid or alkaline mixtures to mercuric compounds, and the iodine is reduced to an iodide. 12. Iodine combines directly with metallic mercury, forming mercurous iodide and then mercuric iodide. 13. Iodine with ammoniated mercury sometimes forms the explosive iodide of nitrogen. 14. In the presence of water iodine combines with metallic iron to form ferrous iodide. 15. In the presence of an alkali iodine changes ferrous compound to ferric and antimonious to antimonic. 16. Arsenous compounds are changed to arsenic by iodine in the presence of an alkali. 17. Iodine with lime and water forms a bleaching mixture. 18. Iodine combines with most metals and with many non-metals, such as chlorine, l>romine, phosphorus, or arsenic- 19. With iodine in a concentrated solution potassium cyanide forms potassium iodide and iodide of cyanogen (M. & M., II. 342). 20. Iodine reacts with tannic acid and water. [See AciDUM Tannicum, No. 12.] 21. Iodine when heated with camphor ■gives hydriodic acid, cymene, carvacrol, laurine, and other bodies (R. & S., III., part v. 427). 22. Iodine with alcohol heated with a fixed alkali yields iodoform. 23. Starch and preparations containing it are turned blue by iodine. If a larger amount of iodine is present, the color will be violet ; and 88 INCOMPATIBILITIES IN PRESCRIPTIONS. if a still larger amount be added, the color changes to blue green. By heating the iodized starch to a temperature of 70° to 80° C. the color is destroyed, but on cooling it again assumes its blue color (P. & J., 265). 24. Iodine bleaches litmus and other vegetable colors. 25. It combines with many of the fixed oils to form additive compounds. 26. It combines with many volatile oils, and in some cases, as with turpentine, it acts with almost explosive violence. 27. In solution iodine slowly forms hydriodic acid. A freshly pre- pared tincture of iodine is precipitated by water, but an old tincture may not be, owing to the presence of the hydriodic acid. 28. Iodine, either in alcoholic solution or dissolved in an aqueous solution of potassium iodide, precipitates nearly all alkaloids from aqueous solutions of their salts. A large amount of alcohol present may prevent the precipitation. The precipitates from water are generally red brown and amorphous. Caffeine and theobromine in dilute solutions are not precipitated by iodine. Liquor Acicli Arsenosi. — This solution contains free arsenous and hydrochloric acids. [See AciDUM Arsenosum and AciDUM Hydrochloricum.] Liquor Amiuonii Acetatis. — Solution of ammonium acetate sometimes contains ammonium carbonate or free acetic acid. [See CARBONATES, AMMONIUM, and AciDUM ACETICUM.] Liquor Arseiii et Hydrargyri lodidi. — i. Dono- van's solution precipitates nearly all alkaloids from aqueous, solutions of their salts. 2. Alkali hydrates precipitate the mercury as the oxide. 3. Silver nitrate is precipitated as silver iodide. [See AciDUM Arsenosum, Acidum Hydro- chloricum, and Hydrargyri Chloridum Corrosivum.] Liquor Calcis. — i. Lime water forms insoluble com- pounds with tannic, tartaric, gallic, citric, and oxalic acids. The compounds are generally more soluble in cold water than in hot. 2. Heat tends to throw the calcium hydrate out of solution. 3. Lime water has all of the incompatibilities of INCOMPATIBILITIES IN PRESCRIPTIONS. 89 the fixed alkali hydrates and of the calcium salts. [See Hydrates, Fixed Alkali, and Calcium.] Liquor Ferri Cliloridi. [See Ferricum and ACIDUM Hydrochloricum.] Liquor Ferri Dialysati. — i. Many organic acids, the alkali hydrates and carbonates, some salts, and acacia precipitate or gelatinize the solution of dialysed iron. 2. It combines with Fowler's solution, precipitating the arsenic combined with ferric hydrate. Liquor Ferri et Amnionii Acetatis. [See Ferri- cum, Ammonium, and Aciuum Aceticum.] Liquor Ferri Subsulpliatis. [See Ferricum and Acidum Sulphuricum.] Liquor lodi Couipositus. [See Iodum and Acidum Hvdriodicum.] Liquor Plumbi Subacetatis. — i. Goulard's extract is alkaline to litmus. 2. It is precipitated by nearly all organic acids, except formic, butyric, acetic, and lactic acids. 3. It precipitates from aqueous solutions nearly all alkaloids, glucosides, and neutral principles. 4. It precipitates albu- min. 5. Mucilage of acacia is gelatinized by a solution of lead subacetate, but when both are diluted with water stringy masses are formed. 6. Lead subacetate precipitates concen- trated solutions of antipyrin. 7. It unites readily with liquid or solid fats (N. D., 974). 8. Lead subacetate has all of the incompatibilities of lead acetate. [See Plumbi Acetas.] Liquor Potassse. [See Potassa.] Liquor Potassii Arsenitis. — i. Fowler's solution is alkaline, and contains some potassium bicarbonate w^hich has been more or less changed to potassium carbonate. It con- sequently has the incompatibilities of a carbonate as well as those of a soluble arsenite. [See CARBONATES and AciDUM Arsenosum.] Liquor Sodse. [See Hydrates, Fixed Alkali.] Liquor Sod^e Cliloratse. — Labarraque's solution has 90 INCOMPATIBILITIES IN PRESCRIPTIONS. about the same incompatibilities as chlorine and soluble chlo- rides. [See ChLORUM and ACIDUM HYDROCHLORICUM.] Liquor Sodii Silicatis. — i. This solution is precipi- tated by alcohol, concentrated mineral acids, or dilute acids with heat. 2. It gelatinizes mucilage of acacia. 3. It is strongly alkaline. Litliii Beiizoas. [See Lithium and Acidum Ben- ZOICUM.] Litliii Salicylas. [See Lithium and Acidum Sali- CYLICUM.] Litliivim. — I. The soluble lithium salts are precipitated from their solutions by soluble carbonates, the precipitate being lithium carbonate. 2. Soluble phosphates precipitate lithium phosphate. 3. With the exception of the carbonate and phosphate, the common lithium salts are generally soluble in water and in alcohol. Lobelia. — i. Lobelia contains the volatile alkaloid lobe- line, which is easily decomposed by alkalies or hot water. 2. It is precipitated by most alkaloidal reagents. [See Alkaloids, Nos. i and 2.] Magnesia. — i. Magnesia combines with acids to form salts. 2. With fifteen times its weight of water it soon forms a gelatinous mass, due to the formation of magnesium hydrate. Magnesium hydrate is slightly soluble in water, and its action is similar to that of the fixed alkalies but weaker. 3. With sixteen times its weight of copaiba mag- nesia makes a thick or solid mass on standing, the copaiba combining to form magnesium copaivate. 4. Magnesia ab- sorbs carbon dioxide from the air. [See Magnesium and Hydrates, Fixed Alkali.] Magnesii Svilphas. [See Magnesium and Acidum SULPHURICUM.J Magnesium. — Soluble salts of magnesium in concen- trated aqueous solution are precipitated: i. by the fixed alkali hydrates and the hydrates of barium, strontium, and calcium, as magnesium hydrate ; 2. by the normal carbonates INCOMPATIBILITIES IN PRESCRIPTIONS. 91 of the fixed alkali metals, as basic carbonate of magnesium ; 3, by the alkaline phosphates, as magnesium phosphate; 4. by alkaline arsenates, as magnesium arsenate; 5. by soluble sulphites, oxalates, or tartrates, as magnesium sulphite, oxalate, or tartrate respectively. 6. Ammonium hydrate or carbonate scarcely precipitates magnesium salts, and may prevent to some extent the precipitation by the fixed alkali hydrates and carbonates. Maiig'aiiuni. — i. Salts of manganese in aqueous solution are precipitated by the fixed alkali hydrates as manganous hydrate, white but soon turning brown in the air from oxi- dation. Ammonium hydrate in the presence of ammonium salts scarcely precipitates manganous salts. 2. The alkali carbonates, phosphates, or cyanides precipitate the man- ganous carbonate, phosphate, or cyanide, all of which are white when first precipitated, but darken on exposure to air. 3. Manganous salts in alkaline mixture are oxidized to manganese dioxide by chlorine, bromine, and iodine. Mel. — I. The presence of honey prevents the precipita- tion of some of the metallic salts by the alkali hydrates. 2. Honey decomposes borax, with liberation of boric acid, the reaction being somewhat similar to that between glycerin and borax. [See Glycerinum, No. i.] 3. Honey when tritu- rated with strong oxidizing agents, such as potassium chlorate or potassium permanganate, is liable to form an explosive mixture. Menthol. — i. Menthol when triturated dry gives a liquid or soft mass with borneol, bromal hydrate, butyl chloral hydrate, camphor, carbolic acid, chloral alcoholate, chloral hydrate, euphorin, exalgin, naphtol, pyrocatechin, pyrogallol, resin, resorcin, thymol, or urethane. 2, Fum- ing nitric acid forms an explosive oil (M. & M., iii. 203). 3. Potassium permanganate in solution decomposes men- thol, forming pimelic, formic, propionic, butyric, and oxy- menthylic acids (M. & M., ill. 203). 4. Chromic acid oxidizes it to dextro- and laevo-menthol (U. S. D., 868). 92 INCOMPATIBILITIES IN PRESCRIPTIONS. 5. Many concentrated acids dissolve menthol, the addition of water precipitating it again. Methiicetiiiuiii. — Methacetin produces a liquid when triturated with carbolic acid, chloral alcoholate, chloral hydrate, or pyrocatechin ; with bromal hydrate or resorcin it gives a stiff mass. Metliyleiie-blue. — i. Tetramethylthionine hydrochlo-^ ride is decomposed by a strong solution of potassium hydrate, liberating the base as a violet precipitate (M. M. R., iv. 359). 2. Reducing agents cause the formation of a color- less substance, which again takes up oxygen, forming methy- lene-blue (M. M. R., iv. 359). 3. Sulphuric acid changes the blue aqueous solution to a bright green color (M. M. R., IV. 359). 4. In aqueous solutions potassium iodide and potassium bichromate precipitate the base as an iodide and a chromate (Allen, III. Part I, 286). Methyl Salicylas. — i. Methyl salicylate, or artificial oil of wintergreen, gives with a dilute solution of a ferric salt a deep violet color, due to the formation of ferric salicylate. 2. Alkali hydrates decompose it, forming methyl alcohol and a salicylate. 3. Methyl salicylate has incompatibilities, quite similar to those of the soluble salicylates. [See Aci- DUM Salic YLicuM.] Morpliiiia. — i. Morphine combines with acids to form salts. 2. Morphine is precipitated from solutions (not too dilute) of its salts by ammonium, potassium, sodium, cal- cium, and barium hydrates, by carbonates of the alkalies and by borax. The precipitate is soluble in a large excess of the above mentioned fixed hydrates, but not so readily in the carbonates. Morphine tartrate is not precipitated by fixed or volatile hydrates (Blyth, 292). 3. The bicarbonates of the alkalies precipitate only a portion of the morphine from neutral solutions of its salts; tartaric acid prevents the pre- cipitation (Watts, III. 1053). 4. Morphine is precipitated from solutions of its salts by lead subacetate (not neutral lead acetate), by potassium chromate, and by the general INCOMPATIBILITIES IN PRESCRIPTIONS. 93 alkaloidal reagents. 5. Potassium cyanide precipitates morphine usually as the free alkaloid, due to the alkalinity of the potassium salt, although some say that morphine cyanide is precipitated. 6. Silver nitrate is reduced by morphine and gives a red coloration (Sohn, 67). 7. Ferric chloride in nearly neutral solution gives a blue coloration, changing to a dirty green. This coloration is prevented or destroyed by excess of acid or alcohol. 8. Nitric acid gives a red color, changing to an orange and then a light yellow. 9. lodates are reduced, liberating iodine. 10. Gold chloride precipi- tates morphine; the precipitate is first yellow, then blue, and finally purple (U. S. D., 879). The gold is reduced. 11. Nitrous acid or spirit of* nitrous ether produces a yellow color with morphine. Morphine is converted into nitroso- morphine, pseudomorphine, and a base C„H,iNOj (M. & M., III. 436). 12. With chlorine a solution of morphine gives a yellow to an orange color, and if ammonia is added it is changed to red brown. 13. Chlorates oxidize morphine. 14. Morphine is oxidized by an alkaline solution of potas- sium permanganate, forming an acid (M. & M., in. 436). With an acid solution of potassium permanganate a green col- oration is produced. 15. Iodine unites with morphine to form iodomorphine (Watts, III. 1052). 16. In a moderately strong aqueous solution morphine is precipitated as the free alkaloid by codeine. 17. Some of the physiological antago- nists are ammonia, amyl nitrite, atropine, caffeine, capsi- cum, cocaine, digitalis, gelsemium, picrotoxin, strychnine, and veratrum. [See Alkaloids.] Miicilago Acacise. [See Acacia.] Mucilago Aiiiyli. [See Amylum.] Mucilago Tragacanthse. [See Tragacantha.] Naplitaliiiuni. — i. Naphtalin is converted into nitro- or dinitro-naphtalin by nitric acid, according to the strength of the acid used (Allen, II. 508). 2. Chlorine and bromine form chloro- and bromo-derivatives. 3. Triturated dry with 94 INCOMPATIBILITIES IN PRESCRIPTIONS. phenol or salol naphtalin produces a liquid. It gives a damp powder with pyrocatechin. Naplitol. — I. Beta-naphtol in aqueous solution imparts a pale green color when ferric chloride is added, and slowly deposits dinaphtol (M. & M., ill. 460). 2. Warming with sulphuric acid, naphtol forms a sulphonic acid (Allen, II. 511). 3. Chlorine or chlorinated lime colors a solution of naphtol a pale green or yellow (Allen, II. 511). 4. A cold saturated aqueous solution of naphtol gives a faint bluish fluorescence with ammonia (U. S. D., 895). 5. Alkaline potassium permanganate oxidizes it to ortho-carboxy-cin- namic acid (M. & M., ill. 460). 6. Beta-naphtol when tritu- rated with antipyrin, borneol, camphor, carbolic acid, ex- algin, menthol, pyrocatechin or urethane gives a liquid or a soft mass. Nitrates. [See Acidum Nitricum.] Nitrites. [See Acidum Nitrosum.] Nux Vomica. [See Strychnina.] Olea Fixa.^i. Fixed oils with solutions of alkali hydrates, lime water, and oxides of many metals, form oleates (soaps) of the base and glycerin. 2. The olein of fixed oils with nitric acid or nitrous acid gas forms the isomeric elaidin, which is solid. 3. Fixed oils absorb and combine with bromine and iodine, forming addition prod- ucts. 4. Concentrated nitric acid and concentrated sul- phuric acid give various color reactions with different oils. 5. Fixed oils do not dissolve readily in glycerin or alcohol. Olea Volatilia. — i. Volatile oils with concentrated sulphuric acid generally give a yellow color, turning brown and sometimes red. 2. Concentrated nitric acid gives color- reactions with many oils. 3. Potassium hydrate saponifies the resinified portions of the oils. 4. Ferric chloride gives colors with some of the oils. [See Ferricum, Nos. 28, 29, 30, and 31.] 5. Iodine reacts violently with some oils, par- ticularly the hydrocarbon oils. INCOMPATIBILITIES IN PRESCRIPTIONS. 95 Oleum ^tliereuin. — i. Ethereal oil with water is slowly decomposed, forming sulphovinic acid and a light oil of wine (N. D., I105). 2. The sulphuric acid is not precipi- tated by the general precipitants of this acid because it exists in the form of sulphovinates, which are soluble (U. S. D., 919). Oleum Amygdalfe Amarre. — i. Oil of bitter almonds contains chiefly benzaldehyde with a little hydrocyanic acid ; the artificial oil consists of benzaldehyde. 2. Benzaldehyde is readily oxidized by the air and by oxidizing" agents, forming benzoic acid, which may crystallize so as to form a mass. Alcohol prevents this to some extent. 3. With an aqueous or alcoholic solution of potassium hydrate it gives benzyl alcohol and potassium benzoate. 4. Ammonia water converts it into crystalline hydrobenzamid, which is again resolved by acids into ammonia and benzoic aldehyde (Allen, III. Part I, 18). A mixture of ammonia and the oil turns yellow on standing. 5. Chlorine converts it into benzoyl chloride. 6. Benzaldehyde with resorcin in the presence of hydrochloric acid forms a resin ; phenol and pyrocatechin act similarly (M. & M., I. 472). 7. With an aqueous solution of sodium bisulphite a crystalline compound is produced. Oleum Auraiitii Corticls. — i. Oil of orange gives a deep-red or a red-brown color with sulphuric acid. 2. Nitric acid gives a greenish-yellow color. 3. Exposed to the air the oil is oxidized and acquires a turpentine odor and taste^ 4. Iodine reacts violently with the oil. Oleum Betulae Volatile. — Oil of sweet birch consists chiefly of methyl salicylate. [See METHYL Salicylas.] Oleum Caryophylll. — i. Oil of cloves dissolved in a little alcohol gives a bright green color when a solution of ferric chloride is added. If the solution of ferric chloride is quite dilute, a blue color is produced, which soon changes to yellow (U. S. P., 275). Clove water gives a yellow or brown solution or precipitate with a solution of ferric chloride. 2. Iodine dissolves quietly in the oil. 3. Nitric acid changes 96 INCOMPATIBILITIES IN PRESCRIPTIONS. its color to a deep red, and if heat be used the bil is converted into oxalic acid (U. S. D., 931). 4. Strong solutions of alkalies convert it into a crystalline mass of potassium euge- nol (N. D., 1117). Oleum Cinnaniomi. — i. Oil of cinnamon dissolved in alcohol gives a brown color with a solution of ferric chloride. Cinnamon water with solution of ferric chloride gives a brown ■color and a slight precipitate. 2. With a saturated solution •of sodium bisulphite the oil solidifies to a crystalline mass. 3. Nitric acid slowly oxidizes it to a crystalline mass of cin- namic acid. 4. Iodine dissolves in it quietly, forming a thick mass (N. D., 11 19). 5- Cinnamon water gives a turbidity -with a solution of lead acetate. Oleum Gaultlieri?e. — Oil of wintergreen is chiefly •methyl salicylate. [See METHYL Salicylas.] Oleum Gossypii. — i. Cottonseed oil with sulphuric acid gives a dark red-brown color. 2. Nitric acid with heat converts the oil into a red-brown mass that partially solidifies on standing. 3. With an alkali hydrate it forms a soap. 4. It combines with iodine to form colorless compounds. Oleum Lavendulfe. — Oil of lavender reacts violently with iodine or bromine. Oleum Limonis. — i. Oil of lemon reacts violently with iodine or bromine. 2. Exposed to air and light it absorbs oxygen, forming a resinous substance and ozone. 3. Con- centrated nitric acid turns it brown and resinous. Oleum Lini. — i. Linseed oil is ignited by fuming nitric acid. Nitric acid of sp. gr. 1.33 turns it green and afterwards brown. 2. Alkali hydrates convert it into a soft soap. 3. An alkaline solution of potassium permanganate converts it into sativic acid (M. & M., III. 147). 4. Exposed to air the oil oxidizes and ultimately becomes solid. If the oil be distributed through cotton, the heat generated by the oxidation maybe sufficient to cause ignition. 5. Iodine and bromine form additive compounds. INCOMPATIBILITIES IN PRESCRIPTIONS. 97 Oleum Mentlise Piperit?e. — i. Oil of peppermint dis- solves iodine quietly and becomes thicker. 2. Chloral hydrate colors the oil red. This is perhaps due to an im- purity in the chloral hydrate (N. D., 1131). 3. An alcoholic solution of the oil with salicylic acid turns green slowly (N. D., 1131). Oleum Olivse. — i. Olive oil heated with nitric acid gives a mass that solidifies. 2. Alkaline hydrates convert it into soap. 8. Iodine combines with it, forming colorless compounds. Oleum Pimentse. — An alcoholic solution of oil of pi- menta with a solution of ferric chloride gives a bright green color. If the iron solution be very dilute, a blue color is formed, changing to green and then yellow (U. S. P., 285). Pimenta water with a solution of ferric chloride gives a pre- cipitate which increases and becomes brown. Oleum Sassafras. — i. Nitric acid reacts violently with oil of sassafras, converting it into a red liquid and finally into a red resin. 2. Sulphuric acid gives the oil a deep red color which soon becomes blackish (U. S. P., 288). 3. Iodine and bromine react with the oil. Oleum Terebintliin^e. — i. Oil of turpentine with a small proportion of sulphuric acid is partially converted into terebene. 2. Dry hydrochloric acid gas with oil of tur- pentine forms a crystalline monohydrochloride of terpene. This has been called " artificial camphor." 3. Chlorine and bromine react so violently that the oil is frequently ignited. 4. Iodine is dissolved by oil of turpentine to form a green solution, which afterwards becomes hot and gives off vapors of iodine and hydriodic acid ; and when considerable quanti- ties of iodine and turpentine oil are brought suddenly together, explosion frequently ensues (Allen, II. 424). 5. Heated with chlorinated lime, oil of turpentine yields chloroform (Allen, II. 424). 6. If oil of turpentine is left in contact with water, it gradually changes into terpin hydrate. This reaction is hastened by the presence of nitric acid (Allen, 11. 424) or by 98 INCOMPATIBILITIES IN PRESCRIPTIONS. alcohol (U. S. D., 971). 7. Nitric acid converts the oil into resinous matter, the violence of the reaction and the products formed depending on the strength of the acid. Some of the products formed are acetic, propionic, butyric, paratoluic, and terebic acids. 8. Fuming nitric acid reacts violently and may set the oil on fire. 9. Strong chromic acid solution oxidizes oil of turpentine to acetic acid and other products (Allen, II. 425). 10. The oil when exposed to air slowly absorbs oxygen and forms a resinous substance, which seems to have the power of producing hydrogen dioxide (U. S. D., 971). Oil of turpentine absorbs oxygen and gives formic and acetic acids, carbon dioxide, ozone, and resinous bodies (Watts, V. 921). Opium. — I. A solution of opium contains many alkaloids and other substances that are generally incompatible with the inorganic salts, general alkaloidal reagents, and many other compounds. [See Morphina, Alkaloids, and Acidum Meconicum.] Oxidizing Agents. — Strong oxidizing agents, such as chromic, nitric, and nitrohydrochloric acids, chromates, nitrates, chlorates, permanganates, should not be triturated with substances that are easily oxidized, as, for instance, sulphur, sulphides, sulphites, hypophosphites, iodine, char- coal, tannic acid, carbolic acid, honey, sugar, glycerin, starch, and vegetable matter. Pancreatinuni. — i. An aqueous solution of pancreatin is precipitated by strong alcohol. 2. The activity of pan- creatin is destroyed by continued contact with acids. 3. Ex- posed to air it becomes less active. Paraldehyduni. — i. Paraldehyde with fixed alkali hydrates forms aldehyde resin which resembles colophony. 2. It is a strong reducing agent and is oxidized to an acid. 3. Chlorine forms substitution products. 4. Hydrocyanic acid combines with aldehydes to form nitrites (M. & M., I. 107). 4. Paraldehyde liberates iodine from iodides (Ph. Era, XVII. 298). INCOMPATIBILITIES IN PRESCRIPTIONS. 9^ Pei>siiiuin. — Pepsin is rendered inert by alkaline sub- stances, by prolonged contact with alcohol, or by tannic acid. Perniaiigauates. [See Potassii Permanganas.] Plieiiacetinuni. — i. Phenacetin in strong aqueous so- lution gives with chromic acid, chlorine, chlorinated lime, iodine, and some other oxidizing- agents colorations varying from pink to red. These colorations are due to the presence of paraphenetidin in the phenacetin, or upon its formation by decomposition of the phenacetin (M. M. R., IV. 359). 2. Heating phenacetin with hydrochloric acid and then adding a solution of ferric chloride gives a red color. 3. Salicylic acid when triturated with phenacetin is said to give a pasty mass. The writer failed to get anything but a dry powder. 4. Phenacetin triturated with carbolic acid, chloral hydrate, or pyrocatechin gives a liquid. 5. It is decomposed by strong acids or alkalies (Scoville, 234). 6. Phenacetin combines with iodine to form a compound known as iodo- phenin. 7. Phenacetin conceals the fluorescence of quinine sulphate, especially in dilute solutions. Pheiiocoll Hydrochloriduin. — i. Phenocoll hy- drochloride in aqueous solution is precipitated by the alkaline hydrates and carbonates as the free base. 2. Piperazin is said to precipitate the base phenocoll when mixed with a strong solution of phenocoll hydrochloride. According to Roe, the best results for making a solution are obtained when the phenocoll salt is from fifty to one hundred per cent, in excess of the piperazin, and each compound should be dis- solved in a portion of water before being mixed (D. C, XXXIX. 14). 3. The fluorescence of quinine sulphate is de- stroyed by phenocoll hydrochloride. Phosphates. [See Acidum Phosphoricum and SoDii Phosphas.] Phosphorus. — i. Phosphorus is oxidized in the air, forming oxides of phosphorus, and may cause fire. 2. A warm solution of potassium or sodium hydrate or lime 100 INCOMPATIBILITIES IN PRESCRIPTIONS. water with phosphorus gives a hypophosphite and phos- phorus hydride gas. 3. In the presence of water, chlorine, bromine, or iodine oxdizes phosphorus and forms phos- phoric acid and hydrochloric, hydrobromic, or hydriodic acid. 4. Phosphorus is oxidized by nitric acid, chromic acid, old oil of turpentine, and other substances rich in oxygen. 5. When phosphorus is triturated with potassium chlorate, chromic oxide, lead dioxide, mercuric oxide, silver oxide, potassium bichromate, potassium nitrate, sulphur, or sul- phides, explosion is liable to take place. Pliysostigniina. — i. Physostigmine is precipitated from aqueous solutions of its salts by the general alkaloidal reagents, except picric acid and platinum chloride. 2. Alka- line hydrates and carbonates precipitate the alkaloid from concentrated aqueous solutions of its salts and give a red •color, changing to yellow, green, and blue (Sohn, 23). The red color is due to the formation of rubreserine (N. D., 122 i). 3. Gold chloride gives a blue coloration. 4. A solution of chlorine or bromine gives a red coloration. 5. Nitric acid gives a yellowish-red color. 6. The free alkaloid precipitates iron as the hydrate from a solution of ferric chloride (N. D., 122 i). 7. Physostigmine is physiologically incompatible with atropine, chloral hydrate, morphine, strychnine, and caf- feine. [See Alkaloids.] Picrotoxiniim. — i. Picrotoxin combines with alkali hydrates, forming soluble compounds; acids added to solu- tions of these cause the precipitation of the picrotoxin. 2. Chloral hydrate is a physiological antagonist. Pilocarpiiite Hydrochloridum. — i. Pilocarpine hydrochloride in aqueous solution is precipitated by the re- agents that generally precipitate alkaloids, except that it is not readily precipitated by alkali hydrates and carbonates. 2. When this alkaloidal salt is mixed with calomel in the presence of moisture a darkening occurs. This is probably due to the separation of metallic mercury while at the same time some mercuric chloride is formed which combines with INCOMPATIBILITIES IN PRESCRIPTIONS. loi the alkaloid. 3. Potassium permanganate oxidizes it to pyridin (M. & M., iv. 275). 4. Atropine has an opposite effect physiologically. Piperazinuni. — i. Piperazin combines with acids to form salts. 2. With an aqueous solution of piperazin alum gives a white precipitate. 3. Ferrous sulphate gives a dark green precipitate which turns brown on standing. 4. Ferric chloride gives a red-brown precipitate. 5. An aqueous solu- tion of piperazin is precipitated by mercuric chloride, copper sulphate, potassium mercuric iodide, Donovan's solution, picric and tannic acids. 6. On account of its strong alka- linity piperazin gives precipitates with solutions of alkaloidal salts and with some inorganic salts. 7. Potassium per- manganate and silver nitrate are reduced by piperazin. 8. Sodium hypochlorite solution forms a body with piperazin that explodes when heated to a temperature of 8o°-8$° C. (M. & M., IV. 349). 9. Bromine water forms the correspond- ing di-bromo-piperazin (M. & M., iv. 349). 10. With spirit of nitrous ether piperaz-in gives a yellow to a red solution. II. Quinine is said to give an amorphous violet-brown body with piperazin (M. & M. , iv. 349). Piperazin gives a white pre- cipitate with a solution of quinine sulphate and destroys the fluorescence. 12. Phenol combines with piperazin. 13. When piperazin is triturated dry with butyl chloral hydrate, acetanilid, antipyrin, carbolic acid, chloral hydrate, or phenacetin, a liquid or soft mass is formed. This is due in some instances to chemical combination and sometimes to the fact that piperazin is very hygroscopic. Plvinibi Acetas. — i. Lead acetate in aqueous solution is precipitated by the fixed alkali hydrates as lead hydrate which is soluble in excess of the alkali hydrate. The precip- itation is prevented by the presence of glycerin and sugar to some extent. 2. Ammonium hydrate does not precipitate lead acetate, except from a concentrated solution. 3. The soluble carbonates precipitate the white basic carbonate of lead. 4. Borax precipitates the white lead borate. Precip- 102 INCOMPATIBILITIES IN PRESCRIPTIONS. itation is prevented to some extent by glycerin and sugar. 5. Sulphuric acid and the soluble sulphates precipitate the white lead sulphate. 6. Hydrochloric acid and the soluble chlorides precipitate from not too dilute solutions of lead acetate the white lead chloride. 7. The soluble bromides precipitate the white lead bromide. 8. The soluble iodides precipitate the yellow lead iodide. 9. Soluble chromates precipitate the yellow lead chromate. 10. Sodium phos- phate precipitates the white lead phosphate. 11. Alkali sulphites precipitate the white lead sulphite. 12. The soluble cyanides precipitate white lead cyanide. 13. Tannic acid and solutions containing it precipitate the yellow-gray lead tannate. 14. Solutions of lead acetate are precipitated by neutral soluble benzoates, citrates, tartrates, and sali- cylates. 15. Pyrogallol gives a white precipitate which be- comes brown and black on exposure to air and light. 16. Lead acetate gives a precipitate with some coloring matters, gums, resins, neutral principles, glucosides, and alkaloids. 1 7. With a solution of opium lead acetate forms the acetates of the alkaloids and the insoluble lead meconateand sulphate. 18. Lead acetate gives a liquid or soft mass when rubbed with aceta- mid, carbolic acid, chloral hydrate, salicylic acid, sodium phosphate, or urea. It gives a stiff mass with pyrocatechin, pyrogallol, resorcin, sodium salicylate, or urethane. Pliiinbi Subacetas. [See Liquor Plumbi Subace- TATIS.] Potassa. — Potassium hydrate has the incompatibilities of the fixed alkali hydrates. [See Hydrates, Fixed Al- kali, and Potassium.] Potassii Acetas. [See Acidum Aceticum.] Potassii Bicarbonas. [See Carbonates.] Potassii Bichronias. [See Acidum Chromicum.] Potassii Bitartras. — i. Cream of tartar combines with the hydrates and carbonates of the alkalies to form neutral soluble salts. 2. Cream of tartar becomes more sol- uble in solutions of borax or boric acid. 3. It is acid in INCOMPATIBILITIES IN PRESCRIPTIONS. 103 Teaction, and has the incompatibilities of tartaric acid. [See AciDUM Tartaricum.] Potassii Bromiclum. [See Acidum Hydrobromi- €UM.] Potassii Carbonas. [See Carbonates.] Potassii Chloras. [See Chlorates.] Potassii Citras. [See Acidum Citricum.] Potassii Cyaiiiduni. — Potassium cyanide is strongly alkaline and usually contains a carbonate. [See AciDUM Hydrocyanicum and Carbonates.] Potassii et Sodii Tartras. — Nearly all acids when added to a strong solution of Rochelle salt combine with the sodium and precipitate the potassium bitartrate. [See Acidum Tartaricum.] Potassii Hypophosphis. [See Acidum Hypophos- PHOROSUM.] Potassii lodidum. — Potassium iodide sometimes con- tains a carbonate as an impurity. [See AciDUM Hydri- ODICUM.] Potassii Mtras. [See Acidum Nitricum.] Potassii Permanganas. — i. Potassium permanganate in acid solution is reduced to the manganous condition by nitrous acid and nitrites, forming nitric acid; 2. by hydro- chloric acid and chlorides, liberating chlorine ; 3. by hydro- bromic acid and bromides, liberating bromine ; 4. by hydri- odic acid and iodides, liberating iodine ; 5. by sulphites and hyposulphites, forming sulphates; 6. by mercurous com- pounds, forming mercuric compounds; 7. by arsenites, forming arsenates; 8. by ferrous compounds, forming ferric compounds; 9. by hypophosphites, forming phosphates ; 10. by ammonia, forming nitrates. 11. With hydrogen dioxide water mixed with sulphuric acid, potassium permanganate forms manganous sulphate, potassium sulphate, water, and oxygen, the oxygen coming from both the permanganate and hydrogen dioxide. 12. Tartaric acid is converted into formic acid and carbon dioxide, more readily in a neutral or alkaline 104 INCOMPATIBILITIES IN PRESCRIPTIONS. mixture (M. & M., IV. 642). 13. Carbolic acid is oxidized. by potassium permanganate, forming oxalic acid and carbon dioxide. 14. Alcohol is oxidized to aldehyde and acetic acid, the manganese dioxide and monoxide being precipitated. 15. Glycerin gives a precipitate similar to that produced by alcohol, and is oxidized to formic, propionic, and tartronic acids and carbon dioxide (M. & M., II. 618). 16. In dilute aqueous solution potassium permanganate is reduced by nearly all organic matter; in concentrated solution the reaction may be so great as to cause explosion. 17. When potassium per- manganate is triturated dry with sulphur, sulphides, reduced iron, hypophosphites, charcoal, sugar, glycerin, alcohol, tannic acid, oxalic acid, picric acid, fats, oils, gums, and other readily oxidizable matter, an explosion is liable to ensue. 18. The permanganates are all soluble in water, except silver, which is sparingly soluble. They are insoluble in alcohol. Potassium. — 1. Potassium salts in the presence of a solution of platinic chloride and hydrochloric acid give a yellow precipitate of a double compound of platinum and potassium chloride. 2. Most neutral potassium salts in not too dilute aqueous solution with sodium bitartrate give a precipitate of potassium bitartrate. 3. A solution of the hydrate or carbonate of potassium with an excess of tartaric acid gives a precipitate of potassium bitartrate, Pyoktaniiin. — i. Pyoktannin in solution is decom- posed slowly in the light. 2. Fixed alkali hydrates added to a solution of pyoktannin decolorize the solution and deposits a red precipitate. 3. Ammonia decolorizes a solu- tion of pyoktannin and gives a purplish precipitate. 4. Pyoktannin is said to be incompatible with mercuric chloride. Pyrocatechin. — i. An alkaline solution of pyrocatechin assumes a green color, changing to brown, and finally black. 2. With a solution of ferric chloride it gives a green color, changed to a violet red by ammonia. 3. With a solution of lead acetate it gives a white precipitate. 4. Nitric acid acts INCOMPATIBILITIES IN PRESCRIPTIONS. 105, violently, converting it into oxalic acid (M. & M., IV. 358). 5 . Ammonium carbonate with water converts the pyrocatechin into pyrocatechuic acid (M. & M. IV. 358). 6. With a con- centrated solution of pyrocatechin lime water gives a green- ish color. 7. It reduces silver nitrate to metallic silver. 8. Pyrocatechin forms a liquid with acetamid, acetanilid, anti- pyrin, borneol, bromal hydrate, butyl chloral hydrate, cam- phor, monobromated camphor, carbolic acid, chloral alco- holate, chloral hydrate, euphorin, exalgin, menthol, metha- cetin, naphtol, phenacetin, pyrogallol, salol, sodium phos- phate, urea, or urethane. It gives a stiff mass with diuretin,. lead acetate, or thymol, and a damp powder with naphtalin or resorcin. Pyrogallol. — i. Pyrogallic acid in aqueous solutioa gradually absorbs oxygen from the air and becomes brown red and acid. The coloration takes place more rapidly in the presence of alkalies, changing to nearly black. 2. With ammonia pyrogallein is formed (M. & M., iv. 359) and the solution becomes red. 3. With a solution of a ferrous sul- phate pyrogallol gives a deep blue solution, changing to green and ultimately red. 4. With a solution of ferric chlo- ride a red color is formed at once, and it is turned to violet by adding ammonia, 5. With a solution of ferric acetate a purple-black coloration is formed. 6. With lead acetate pyrogallol gives a white precipitate which turns dark on ex- posure. 7. With lime water a purple color is produced, rapidly changing to brown. 8. Pyrogallic acid is changed to purpurogallin by an alcoholic solution of silver nitrate, by an aqueous solution of potassium permanganate, or by an aqueous solution of ferric chloride in excess (M. & M,, iv. 359). 9. Pyrogallol in aqueous solutions reduces salts of silver, mercury, and gold, and it is oxidized to acetic and oxalic acids (Richter, 695). 10. Pyrogallol gives a liquid or soft mass when rubbed with acetamid, antipyrin, camphor, carbolic acid, exalgin, menthol, pyrocatechin, urea, or lo6 INCOMPATIBILITIES IN PRESCRIPTIONS. urethane. It gives a stiff mass with diuretin, lead acetate, or sodium phosphate. Pyroxylinum. — i. Soluble gun-cotton when damp undergoes decomposition, and may ignite or cause an ex- plosion. 2. Treated with alkalies in concentrated solution it is decomposed, giving up its nitric acid. 3. The nitro- cellulose is converted back to cellulose by reducing agents, such as ferrous salts or alkali sulphides (Richter, 514). [See COLLODIUM.] Quiniiia. — i. Quinine unites with acids to form salts. 2. Quinine is precipitated from aqueous solutions of its salts by all the reagents mentioned under Alkaloids, Nos. 2 and 3, except bromides and iodides; in concentrated solutions these may also give precipitates. 3. Hypophosphorous acid aids the solution of quinine sulphate, but if added in sufficient -amount potassium hypophosphite destroys the fluorescence and causes precipitation. 4. Quinine is precipitated from solution of its salts by the alkali acetates as the voluminous quinine acetate. [See AciDUM ACETICUM, No. 4.] 5. Citric acid aids the solution of quinine sulphate in water. Adding an alkali citrate destroys the fluorescence and precipitates the quinine. 6. Quinine is precipitated from its concentrated aqueous solutions by benzoates, salicylates, and tartrates, the precipitate generally being bulky. 7. Quinine gives a blue fluorescence with nearly all acids that contain oxygen. 8. The fluorescence is destroyed by the halogen acids, salts of the halogens, antipyrin, acetanilid, phenacetin, phenocoll hydrochloride, or piperazin. 9. When the alkaloid quinine is heated with solutions of ammoniacal salts ammonia gas is liberated. 10. Quinine sulphate is oxidized by potassium permanganate to pyridin tricarboxylic acid, oxalic acid, and ammonia (M. & M., iv. 375). 11. An aqueous solution of quinine sulphate in sunlight turns yellow and then brown, and gives a brown flocculent precipitate, due to the formation of quiniretin (N. D., 135 1). 12. When quinine sulphate is rubbed with thymol it gives a soft mass; with chloral hydrate INCOMPATIBILITIES IN PRESCRIPTIONS. 107 it gives a damp powder or stiff mass. 13. The solubility of quinine sulphate in water is increased by the presence of cer- tain compounds, as ammonium chloride, potassium nitrate, and antipyrin. [See Alkaloids.] Kesiiia. — i. Pine resin when triturated with menthol, salol, carbolic acid, or urethane makes a liquid or sticky mass. 2. Nitric acid oxidizes it to isophthalic and trimellitic acids (M. & M., i. i). 3. Potassium permanganate oxi- dizes it to formic, acetic, and carbonic acids (M. & M., i. i). Resinse. — i. With aqueous solutions of alkali hydrates or carbonates resins form resin soaps which are generally sol- uble in water. 2. Nitric acid converts them into artificial tannin (U. S. D., 1 150). 3. Concentrated sulphuric acid dissolves many of the resins with decomposition and gives <;olor reactions with some. 4. Tincture of ferric chloride gives different colors with resinous substances. [See Ferri- CUM, No. 26.] 5, Alcohol containing hydrochloric acid is colored red to violet by myrrh ; yellowish brown to green by guaiac ; yellow, changing through brown to cherry-red, by benzoin or balsam of Tolu ; greenish, changing to dingy vio- let, by asafoetida ; and brown by some other resins. Resorciiiimi. — i. An aqueous solution exposed to the air becomes red and brown. This reaction is hastened by the presence of alkalies. 2. With a dilute solution of ferric chloride resorcin gives a violet coloration. 3. With chlori- nated lime or soda a solution of resorcin gives a violet color- ation, changing to yellow. 4. Nitrous acid or spirit of nitrous ether gives a dark red solution with resorcin. Nitrous acid acting on a dilute solution of resorcin produces di-nitroso- resorcin (Richter, 690). 5. Resorcin produces a liquid or soft mass when triturated with acetamid, acetanilid, ammonol, antipyrin, borneol, camphor, carbolic acid, chloral alcohol- ate, euphorin, exalgin, menthol, methacetin, or urethane. With lead acetate, pyrocatechin, or sodium phosphate it gives a slightly damp powder, which quickly dries. Saccharvim. — i. A solution of sugar heated with lime, Io8 INCOMPATIBILITIES IN PRESCRIPTIONS. magnesia, litharge, and other metaUic oxides and hydrates form saccharates, chemical compounds which are more or less- soluble in water. 2. The presence of sugar hinders or pre- vents the precipitation, or dissolves the precipitate, of many- metallic hydrates or oxides which are normally formed when alkali hydrates are added to solutions of metallic salts. The interference is most marked in case of lead, antimony, cop- per, mercuric, ferrous, ferric, aluminum, zinc, calcium, and magnesium salts. 3. Very strong nitric acid with sugar, in the cold, forms explosive nitrosaccharose (Allen, i. 214). Moderately concentrated nitric acid converts sugar into sac- charic and tartaric acids, and with heat into oxalic acid and carbon dioxide (Allen, I. 214, 240), 4. With concentrated sulphuric acid sugar is decomposed, forming carbon, while formic acid, sulphur dioxide, and other gases are given off (Allen, I. 2 1 5). 5 . Sugar warmed with dilute solutions of acids,. or heated for some time with v/ater, is changed to invert- sugar. 6. When a concentrated solution of sugar and potas- sium hydrate is heated, carbon dioxide, acetone, acetic, propionic, and oxalic acids are formed (M. & M., iv. 551). 7. Chlorine or bromine oxidizes sugar to gluconic acid, glu-^ cose and other products. The same reaction takes place in the presence of lead or silver oxide (M. & M., iv. 551). 8. Iodine with potassium carbonate and sugar yields a little iodoform (M. & M., IV. 551). 9. Dilute chromic acid solution oxidizes sugar to oxalic, formic, and carbonic acids (M. & M., IV. 551). 10. Potassium permanganate converts sugar into oxalic, formic, and carbonic acids (M. & M., iv. 551). II. Sugar triturated with potassium chlorate, permanga- nate, or bichromate, or with other strong oxidizing agents, is liable to cause an explosion. Sacchtiruin Lactis. — i. Milk-sugar in alkaline solution reduces salts of silver, mercury, bismuth, or copper (N. D., 1398). 2. Nitric acid first inverts milk-sugar and then forms mucic and saccharic acids, and if heated forms tartaric and racemic acids and finally oxalic acid. 3. Dilute acids invert INCOMPATIBILITIES IN PRESCRIPTIONS. 109 milk-sugar, forming dextrose and galactose. 4, A mixture of sulphuric and nitric acids with milk-sugar gives lactose pentanitrate, which is explosive (M. & M., IV. 553). 5. Chro- mic acid with milk-sugar yields aldehyde (M. & M., IV. 553). 6. Alkali permanganates oxidize milk-sugar. 7. Silver oxide oxidizes it, forming oxalic, glycoUic, and lactonic acids (M, & M., IV. 553). 8. Milk-sugar with a solution of iodine and sodium bicarbonate yields a little iodoform (M. & M,, IV. 553). 9. Triturated with oxidizing agents, it is liable to cause an explosion. Salicinuin. — i. Salicin is not readily precipitated by any of the common precipitants, 2. Dilute acids or water with heat changes it to glucose and saligenin. Salicylates. [See Acidum Salicylicum.] Salocoll. — I. Phenocoll salicylate gives a violet-red color with a tincture of iron. 2. Triturated with chloral hydrate it liquefies. Salol. — I. Salol in alcoholic solution gives a violet color when a dilute solution of ferric chloride is added to it. If, however, a little of the salol solution be added to the ferric chloride solution, a white cloudiness, but no violet color, will appear (U. S. P., 344). In aqueous solution no increase of color results. 2. Bromine water added to an alcoholic solu- tion of salol will cause the formation of long needle-shaped crystals, consisting of a bromo-derivative. 3. Strong solu- tions of alkalies heated with salol saponify it, forming a salicylate and carbolic acid (Allen, III. part I. 60). 4. When salol is triturated dry with borneol, camphor, monobromated camphor, carbolic acid, chloral alcoholate, chloral hy- drate, euphorin, exalgin, naphtalin, pyrocatechin, resin, thymol, trional, or urethane, a liquid or soft mass results. It gives a slightly damp powder with antipyrin, quickly drying. Salophen. — Salophen, on account of the salicylic acid which it contains, gives a violet-red color with tincture of iron. no ■ INCOMPATIBILITIES IN PRESCRIPTIONS. Santonin. — i. Santonin on exposure to light turns yellow, forming photo-santonic acid and a yellow-resinous body (N. D,, 1414). 2. With alkali hydrates in solution it forms santoninates, which are soluble in water. 3. An aqueous solution of santoninate is precipitated by lead acetate or lead subacetate as lead santoninate. It is also precipi- tated by tannic acid, ferrous sulphate, copper sulphate, chlorine water, and by acids if the solution of santoninate is not too dilute. 4. Santonin is turned pink or red by potas- sium hydrate in the presence of alcohol. 5. Heated with nitric acid, santonin forms carbon dioxide, succinic, oxalic, and acetic acids (M. & M., IV. 429). Sapo. — I. Aqueous solutions of soap are decomposed by mineral acids, which combine with the base, liberating the free fat acid. 2. Aqueous solutions of metallic salts give precipitates of metallic oleates with soaps. 3. Soap is fre- quently alkaline, and when so it makes a black mixture with calomel, due to the mercurous oxide formed. 4. It may precipitate hydrates or oxides from solutions of metallic salts. Soda. — Sodium hydrate has the incompatibilities of the fixed alkali hydrates. [See HYDRATES, Fixed Alkali.] Sodii Arsenas. — Sodium arsenate is frequently alka- line. [See AciDUM Arsenicum.] Sodii Benzoas. — [See Acidum Benzoicum.] Sodii Boras. — i. A saturated solution of borax gela- tinizes mucilage of acacia. [See Acacia, No. 5.] 2. Borax is alkaline in reaction and precipitates metallic compounds and alkaloids from solutions of their salts. Glycerin pre- vents this by decomposing the borax. 3. Glycerin and borax react in the presence of water, liberating boric acid. [See Glycerinum, No. i.] Glucose, some other forms of sugar, and honey cause a similar reaction. 4, When tritu- rated with alum, borax forms a damp powder or sticky mass. Chemical reaction takes place and the water of crystallization is liberated. 5. Borax liberates chloroform from a solution of chloral hydrate. 6. Sugar makes borax more soluble in INCOMPATIBILITIES IN PRESCRIPTIONS. m water (VV. D., xvil. 6i). 7. Borax increases the solubility in water of boric, benzoic, salicylic, and stearic acids, various resins, and oils. 8. Borax forms with many of the weaker acids, double salts in which the boric acid appears to act the part of a base. 9. When tartaric acid and borax are mixed in solution in proper proportions boric acid separates; if the quantity of tartaric acid is gradually increased, the quantity of boric acid also increases up to a certain point, beyond which it diminishes (Watts, I. 648). [See AciDUM BORICUM.] Sodii Bromidum. [SeeAcmuM Hydrobromicum.] Sodii Carbonas. [See Carbonates.] Sodii Chloridum. [See Acidum Hydrochlori- CUM.] Sodii Hypophosphis. [See Acidum Hypophos- phorosum.] Sodii Hyposvilphis. [See Sodii Thiosulphas.] Sodii lodiiim. [See Acidum Hydriodicum.] Sodii Nitris. [See Acidum Nitrosum.] Sodii Phosphas. — i. The official sodium phosphate is slightly alkaline in reaction, and precipitates some of the alkaloids from aqueous solutions of their salts, and also neutral solutions of salts of nearly all common metals. 2. Sodium phosphate gives a liquid or soft mass when rubbed with acetamid, carbolic acid, chloral hydrate, lead acetate^ pyrocatechin, pyrogallol, or salicylic acid. It forms a slightly damp powder with antipyrin, resorcin, or sodium salicylate. [See Acidum Phosphoricum.] Sodii Fyrophosphas. [See pyrophosphoric acid under Acidum Phosphoricum.] Sodii Salicylas. [See Acidum Salicylicum.] Sodii Sulphas. [See Acidum Sulphuricum.] Sodii Thiosulphas. — i. Sodium thiosulphate (hypo- sulphite) in aqueous solution is decomposed by nearly all acids, forming sulphur, and sulphurous acid. 2. Aqueous solutions of thiosulphates are decomposed into hydrogen sul- phide and sulphuric acid when boiled (M. & M., IV. 705). 112 INCOMPATIBILITIES IN PRESCRIPTIONS. 3. Sodium thiosulphate precipitates, as thiosulphates, solu- tions of barium chloride, silver nitrate, lead acetate, and mercurous nitrate. The precipitates arc white, but those ■of the last three salts turn black on standing, forming the sulphide of the metal and sulphuric acid. 4. Sodium thio- sulphate with a solution of ferric chloride gives a dark violet •color, due to ferric thiosulphate. The solution soon loses its color because the salt formed changes to ferrous sulphate. 5 . In acid solution sodium hyposulphite reduces iodine to hydriodic acid; 6. chlorates to chlorine and hydrochloric acid; 7. chromates to chromic salts; 8. permanganates to manganic salts; 9. arsenic compounds to arsenous. 10. Sodium thio- sulphate forms double thiosulphates with many metallic salts. II. Solutions of sodium thiosulphate dissolve silver iodide, silver bromide, silver chloride, mercuric iodide, and other salts (Watts, V. 630). 12. In very dilute solutions it prevents the precipitation of some of the alkaloids by gold chloride. It combines with the gold to form a double thiosulphate. 13. An acidulated solution bleaches vegetable colors on account of its reducing properties. 14. When sodium thio- sulphate is triturated with potassium chlorate, nitrate, or per- manganate, or other strong oxidizing agents, explosion is liable to take place. Spiritus. — Water causes a separation of the volatile sub- stance from all of the official spirits except spirit of nitrous ether, spirit of ammonia, whiskey, and brandy. They all contain alcohol and consequently have the reactions of alcohol. Spiritus ^theris Compositus. [See Oleum ^the- REUM.] Spiritus ^tlieris Nitrosi. — i. The ethyl nitrite in the spirit of nitrous ether is decomposed by alkali hydrates, forming alcohol and a nitrite of the alkali. 2, The spirit of nitrous ether readily undergoes decomposition, forming alco- hol, aldehyde, nitrous acid, nitric acid, and other products. INCOMPATIBILITIES IN PRESCRIPTIONS. 113 3. The spirit has the incompatibilities mentioned under nitrous acid. [See Acidum NiTROSUM.] Spiritus Amiuonise. — Spirit of ammonia has the same incompatibilities as water of ammonia, except as they are modified by the alcohol. With solutions of alkaloidal salts the ammonia liberates the alkaloids, but the alcohol has a tendency to keep them in solution. [See HYDRATE, Vola- tile Alkali.] Spiritus Animoniie Aroinaticus. — The incompati- bilities of this preparation are similar to those of the spirit of ammonia, and in addition the ammonium carbonate with acids liberates carbon dioxide. Aqueous or weak alcoholic liquids cause the separation of the aromatic oils. Spiritus Camphorae. [See Camphora and Spiritus.] Spiritus Frunienti. — Whiskey usually contains a little tannic acid. Spiritus Gaultlierise. [See Methyl Salicylas and Spiritus.] Spiritus Glonoini. — If the alcohol is allowed to evap- orate the nitroglycerin may become sufficiently concentrated to cause explosion when struck. [See Glonoinum and Spiritus.] Spiritus Vini Gallici. — Brandy usually contains a little acetic and tannic acids. Stramonium. [See Atropina.] Strontii Bromidum. [See Strontium and Acidum Hydrobromicum.] Strontii Lactas. [See Strontium and Acidum Lac- ticum.] Strontium. — i . Salts of strontium in aqueous solution are precipitated by the soluble carbonates, phosphates, or oxa- lates as strontium carbonate, phosphate, or oxalate. 2. The soluble sulphates, chromates, or alkali hydrates precipitate from concentrated solutions the strontium sulphate, chromate, or hydrate. Stryclinina. — i. Strychnine combines with acids to 114 INCOMPATIBILITIES IN PRESCRIPTIONS. form salts. 2. Strychnine salts in aqueous solution are pre- cipitated by the reagents mentioned under ALKALOIDS, Nos. 2 and 3. 3. In rather strong solutions of strychnine sulphate the soluble chlorides, bromides, and especially the iodides are liable to cause precipitation of the strychnine. The pre- cipitation may not take place for several days. In explaining the cause of the trouble several factors must be taken into consideration. Frequently the commercial samples of the alkali iodides and bromides are alkaline from the carbonate which was left in to aid their keeping, and this alkali would liberate and precipitate the strychnine. The compound which potassium iodide forms with strychnine is only sparingly sol- uble in water, but the corresponding compounds formed with potassium chloride and bromide are more soluble. Some writers partially explain the precipitation by saying that the compounds formed are less soluble in water containing the inorganic salts than they are in water alone. Alcohol tends to prevent the precipitation. 4. Hydrochloric acid added to a solution of strychnine hydrochloride gives a crystalline precipitate (M. & M., iv. 517). 5. Alkaline substances like sodium phosphate, potassium cyanide, sodium arsenate, and Fowler's solution will cause a precipitation when added to an aqueous solution of a strychnine salt. 6. Precipitation by gold chloride is prevented to some extent by adding to the gold chloride an equal weight of sodium thiosulphate. [See AuRi ET SODii Chlorodi, No. i.] 7. Strong nitric acid if hot converts the alkaloid into the yellow explosive compound which is probably the nitrate of nitrostrychnine (Watts, V. 440). 8. One dram of dilute nitrohydrochloric acid with seven drams of water containing one fourth of a grain of strychnine sulphate gives a yellow coloration in a few days. In stronger solutions the change takes place more quickly. The chemical products have not been definitely determined. 9. Potassium permanganate in alkaline solu- tion yields ammonia, oxalic acid, carbon dioxide, and another crystalline acid, but in acid solution potassium permanganate INCOMPATIBILITIES IN PRESCRIPTIONS. 115 gives an amorphous acid with strychnine (M. & M., iv. 517). 10. The physiological incompatibilities are atropine, aconite, morphine, chloral hydrate, potassium bromide, physostig- mine, hydrocyanic acid, amyl nitrite, chloroform, alcohol, digitalis, curarine, nicotine, paraldehyde, and urethane. Sulphates. [See Acidum Sulphuricum.] Sulphites. [See Acidum Sulphurosum.] Siilphoiial. — I. Sulphonal is not readily acted upon by alkalies, acids, or oxidizing agents. 2. It liquefies when triturated with chloral hydrate. Sulphur. — Sulphur readily dissolves in hot aqueous solutions of hydrates of potassium, sodium, barium, or calcium, forming polysulphides and thiosulphates. 2. Tritu- rated dry with strong oxidizing agents, as potassium chlorate or permanganate, explosion is liable to occur. Syrupus Acidi Hydriodici. — Syrup of hydriodic acid sometimes becomes yellow or brown, due to the formation of iodine. [See Saccharum, Acidum Hydriodicum, and lODUM.] Syrupus Allii, — Syrup of garlic darkens in the light. It contains acetic acid. [See Acidum Aceticum.] Syrupus Calcis. [See Saccharum and Liquor Calcis.] Syrupus Ferri lodidi. — Syrup iodide of iron has the incompatibilities of soluble iodides and of ferrous salts, modified by the presence of sugar. [See Ferrosum and Acidum Hydriodicum.] Syrupus Hypophosphltum. [See Acidum Hypo- PHOSPHOROSUM.] Syrui>us Ipecacuanhge. — Syrup of ipecac contains acetic acid. Syrupus Scillae. — Syrup of squills contains acetic acid. Tannates. [See Acidum Tannicum.] Tartrates. [See Acidum Tartaricum.] Terebenuni. — i. Terebene on exposure to air and light resinifies and becomes acid. 2. It combines with. Il6 INCOMPATIBILITIES IN PRESCRIPTIONS. chlorine, bromine, and iodine to form additive products. 3. In many reactions it resembles oil of turpentine. Tlieobroniiiia. — i. Theobromine acts like a weak base, and also like a weak acid. 2. It combines with strong acids to form salts that are quite readily decomposed by water. 3. It dissolves in an excess of an alkali hydrate solution. 4. From an aqueous solution theobromine gives a crystalline pre- cipitate with silver nitrate, mercuric chloride, and gold chloride. 5. With many of the general alkaloidal reagents it gives no precipitate. Thiol. — Thiol is precipitated from its aqueous solutions by alkali hydrates, mineral acids, and metallic salts (Cob- lentz, yy). Thymol. — i. Thymol unites with alkalies to form sol- uble salts (U. S. D., 1360). 2. With excess of bromine water solutions of thymol yield a yellowish-white precipitate of a bromo-derivative, which gradually collects to form globules of a yellowish liquid (Allen, II. 449). 3. A solution of thymol with iodine and potassium hydrate gives a red amorphous precipitate of iodothymol (M. & M., IV. 715). 4. Spirit of nitrous ether gives a green and then a brown color, changing the thymol to nitroso-thymol. 5. Thymol absorbs ammonia-gas and becomes liquid (M. & M., IV. 715). 6. Thymol reduces gold and platinum from solutions of their salts. 7. Chromic acid oxidizes thymol to thymoquinone (M. & M., IV. 715). 8. Thymol gives a liquid or soft mass when rubbed with acetamid, acetanilid, antipyrin, borneol, camphor, monobromated camphor, carbolic acid, chloral alcoholate, chloral hydrate, euphorin, exalgin, menthol, pyrocatechin, quinine sulphate, resin, salol, or urethane. It is said to liquefy with butyl chloral hydrate. Tinctura Ferri Chloridi. — Tincture of ferric chloride contains free hydrochloric acid. [See Ferricum and AciDUM Hydrochloricum.] Tinctura lodi. — An old tincture of iodine usually con- INCOMPATIBILITIES IN PRESCRIPTIONS. 117 tains some hydriodic acid, which prevents the precipitation of the iodine when water is added. [See lODUM.] Tolypyrin. — Tolypyrin gives the same color reactions with ferric chloride and spirit of nitrous ether as antipyrin (Coblentz, 79). Tragacaiitha. — i. Tragacanth is colored yellow by a solution of sodium hydrate (Allen, i. 355). 2. An aqueous mixture is thickened by alcohol, and by neutral and basic lead acetate (not coagulated by borax, silicates, or ferric salts) (Allen, i. 355). Trional. — i. Trionalwhen rubbed with chloral hydrate or salol gives a liquid or soft mass. Urea. — Urea becomes soft or liquid when triturated with bromal hydrate, chloral alcoholate, chloral hydrate, lead acetate, pyrocatechin, or pyrogallol. Uretliaiiuiii. — i. Urethane in the presence of iodine and an alkaline hydrate or carbonate produces iodoform. 2. Urethane with an alcoholic solution of potassium hydrate gives large crystals of potassium cyanate (M. & M., i. 679). 3. When urethane is triturated in a mortar with acetamid antipyrin, borneol, bromal hydrate, butyl chloral hydrate, camphor, carbolic acid, chloral alcoholate, chloral hydrate, euphorin, exalgin, menthol, naphtol, pyrocatechin, pyrogal- lol, resin, resorcin, salicylic acid, salol, thymol, or benzoic acid, a liquid is produced. Viiium. — Wine generally contains some tannic acid. [See AciDUM Tannicum and ALCOHOL.] Vitellus. [See Albumin.] Ziiici Cliloricluni. — Zinc chloride, like gold and mer- curic chlorides, has a strong tendency to combine with organic bases, as strychnine, morphine, and quinine (U. S. D., 1469). [See ZiNCUM and AciDUM Hydrochloricum.] Zinci Sulphas. [See Zincum and Acidum Sulphur- ICUM.] Ziiiciim. — I. Zinc salts in aqueous solutions are precip- itated by the fixed alkali hydrates as zinc hydrate which is Il8 INCOMPATIBILITIES IN PRESCRIPTIONS. soluble in excess of the alkali hydrate. 2. Zinc salts are precipitated by soluble carbonates, phosphates, arsenates, or cyanides, as the basic carbonate, phosphate, arsenate, or cyanide. 3. Borax gives a precipitate of zinc borate or a mixture of the borate and hydrate. 4. Tannic acid gives a precipitate with concentrated solutions of zinc salts. 5. Zinc salts coagulate albumin. PART II. PRESCRIPTIONS JVITH CRITICISMS, In studying the following prescriptions the student should try to make out for himself, so far as possible, wherein the trouble lies, and what he would do to prevent or remedy it, before referring to the notes. In order not to overlook any of the incompatibilities it is suggested that he find out what effect, if any, the first ingredient may have on each of the others ; then the second ingredient, the third, and so on. Then, taking the prescription as a whole, he should determine the color that will be produced, the nature and color of the precipitate, how one incompatibility will be modified by another, etc. The student should practice trans- lating the Latin into English, and the English into Latin. The majority of prescriptions which follow should be filled, unless in the reaction there is some more active or dangerous compound formed. It must not be forgotten that a variation in the proportions of ingredients modifies the results of com- bination. Hydrargyri chloridi cor., gr. ij Potassii iodidi, 3 ij Syrupi rhei aromatici, f. § iv Elixiris cinchonse, f. 3 iv Misce et signa : Teaspoonful three times a day. ^ 8. Quininas sulphatis, gr. xx Acidi sulphurici aromat., f. 3 ss Ammonii carbonatis, 3 j Syrupi aurantii, q. s. ad f. 3 iv M. S. Cochleare parvum t. i. d. I^ 3. Calomel, Potassium chlorate, Sugar, povvd.. Mix and make six powders Label : One every two hours. gr- vj 3j 3j 3 4. 3 iiss Ammonii carbonatis, Syrupi tolutani, Syrupi scillse, aa. f, Misce et fiat solutio. Sig. Teaspoonful when cough »J ing. 119 120 INCOMPATIBILITIES IN PRESCRIPTIONS. 5. ^ Quininae sulphatis, Olei carophylli, Potassii jiermanganatis, Acidi sulphur, aromat., Mucilag. acaci^e, q. s. adf. AT. S. Tablespoonful three hours. 3ij gtt. ij gr. iij f. 3ij 3 viij every 6. I^ Tincturse guaiaci, Muc. acaciffi, aa. f. § j M. S. Teaspoonful every three hours. 7. Bismuthi subnitratis, 3 ij Sodii hypophosphitis, 3 j Extract! nucis vomicae, gr. v Misce, fiat pulvis et divide in partes aequales No. xxv. 8. IJ Hydrargyri chloridi cor., gr. \ Sodii iodidi, Ammonii iodidi, aa. 3 ij Potassii chioratis, 3 j Aquae, f.^3 j S\ rupi sarsaparillae co., f. 3 iv M. S. Teaspoonful in wine- glass of water after each meal. 9. U Potassium chlorate, gr. xl Sodium hypophosphite, gr, xxx Water, enough to make f. 3 xx Mix and label : Use as gar- gle. 10. Borax, Zinc sulphate, aa. 3 ss Mix. Dissolve one teaspoon- ful in cup of water. 11. U Extracti buchu fl., f. 35$; Spiritus aetheris nitrosi, f • 3 j Potassii acetatis, 3 ij Syrupi, q. s. ad f. 3 iv Misce et signa : Teaspoonful half hour after meals. 12. ^ Tinct. digitalis, f. 3 ij' Tinct. ferri chloridi, f. 3 iss. Acidi phosphorici diluti, f • 3 j, AqucC, q. s. ad f. 3 ij M. S. Teaspoonful in some water twice a day. 13. U Quininae sulphatis, gr. xx Plumbi acetatis, gr. xl Bismuthi subnitratis, 3 ss. Syrupi aurantii cort., q. s. ad f. 3 iv M. S. Teaspoonful every four hours. U 14. Sugar of lead, 3 ss Alum, gr. XV Rose water, f. 3 iv Mix and label : Lotion. 15. Quininae sulph., gr. xvj Acidi tannici, 3j Acidi sulphurici arom., TT|,v Syr. eriodictyi arom., q. s. ad f. 3 ij M. S. Teaspoonful twice a day. INCOMPATIBILITIES IN PRESCRIPTIONS. 121 16. Olei morrhuae, Syr. ferri iodidi, Olei gaultheriae, Syrupi, Liquoris calcis, TTlv f. 3xv M. S. Dessertspoonful twice a day. U 17. Liq. arseni et hydrarg. iodidi, lo Cc. Potassii iodidi, 5 Gm. Quininse sulphatis, 2 Gm. Acidi sulphurici aromat., q. s. Syrupi, q. s. ad 300 Cc. M. S. 4 Cc. after each meal. ^ 18. Sodii salicylatis, gr. xx Quininae sulphatis, gr. xx Syrupi zingiberis, f. 3 ij M. S. Teaspoonful doses. 19. 3 21. Liquoris acidi arsenosi, f. 3j Hydrargyri chlor. cor., gr. j Strychninse sulphatis, gr. j Spiritus vini rectificati, f. 3 j Aquae, f. 3 j Misce. Signa : Teaspoonful night and morning. 20. ^ Potassii bromidi, 3 iij Chloralis, 3 iv Elixiris aromatici, q. s. ad f. 3 ij M. S. Take one teaspoonful at night. 5 3 ss gr. xl Plumbi subacetatis, Zinci sulphatis, Tinct. catechu co., Tincturae opii. aa. f. 3 ss Aquae, q. s. ad f. 3 viij M. S. Injection. Shake well before using. 22. ^ Hydrargyri chloridi cor., gr. iij Albuminis, 3 iss Aquae, q. s. ad f. 3 x Misce et cola. Signa: Teaspoonful three times a day. 23. n Sodii phosphatis, 3 v Syrupi rhei, f. 3 iv Syrupi, f. 3 ss Aquae, q. s. ad 3 ij M. S. Teaspoonful in a little water before meals. 24. ^ Ammonii carbonatis, gr. xx Ammonii chloridi, gr. xxx Syrupi allii, f. 3 j Aquae, q. s. ad f. 3 ij M. S. One-half teaspoonful as required. 25. 3 Sodii boratis, gr. x Zinci sulphatis, gr. ij Aquae camphorae, f . 3 j Aquae rosae, q. s. ad f 3 j M. S. Put one drop in each eye night and morning. 122 INCOMPATIBILITIES IN PRESCRIPTIONS. 26. B Syrupi scillse, Syrupi ipecac, aa. f. 3 j Syrupi eridictyi arom., f. 3 ij Potassii iodidi, 3] Spiritus setheris nit., f. 3 ij Glycerini, f. 3 iv Syrupi acidi citrici, q. s. ad f. 3 iij Misce. Signa : Teaspoonful when coughing. 27. 3 f.ij Tinct. ferri chlor., Tinct. iodi comp., Liq. pot. arsenit., Ac. phosphor, dil., aa. f. 3 iv Quininae sulph., 3 j Rhei pulv., 3 ss Aquae, q. s. ad f. 3 viij Misce. Sig. Teaspoonful after meals. 28. n Quinine sulphate, 3 j Stryclinine sulphate, gr. j Sulphuric acid dil., 3 ij Iron pyrophosphate, sol., 3 j Syrup ginger, enough to make f. 3 vj Mix. Teaspoonful three times a day. 29. n Iodine, gr. xxx Spirit of camphor, f. 1 j. Soap liniment, f. 1 iij Mix and label : Apply as di- rected. n 30. Pepsini saccharati, 3 ij Bismuthi et amnion, cit., 3 j Acidi hydrochlorici dil., gtt. xl Aquae, f. 3 ij Misce et fiat solutio. Sig. Dose, one teaspoonful. 31. Sodii hypophosphitis, gr. xx Acidi sulphurosi, 3 j Aquse cinnamomi, q. s. ad f. 3 ij M. S. Teaspoonful for vom- iting. 32. 5 Hydrargyri chlor. mit., gr. ij Potassii iodidi, gr. xl Misce et fiat pulvis et in char- tulas decem divide. Signa: One powder after each meal. 33. 3 Tinct. nucis vom., Acidi nitromur., aa. f. 3 ij Elixiris quininae co., N. F., f. 3 iiiss M. S. Teaspoonful in an ounce of water after meals. 34. 5 3 ss 3j gr. V Quininse sulphatis, Potassii iodidi, Strychninae sulph., Tinct. cardam. co., Syr. zingiber., aa. f. 3 ij Aquae fontanae, q. s. ad O. ss M. S. Take one tablespoon- ful night and morning. INCOMPATIBILITIES IN PRESCRIPTIONS. 123 35. 3 Ammonii carbonatis, 3 j Syrupi ipecacuanhse, f . 3 j Vini pepsini, Misturge amygdalae, aa. f. 3 j M. S. Teaspoonful in milk every three hours. n 36. Potassii chloratis, gr. iv Sulphuris praecip., gr. vj Antimonii sulphur., gr. j Sacchari, gr. x Tere. Fiant chartulae 2. Signa : Insufflation, 37. Vini ipecacuanhae, f , 3 iij Syrupi scillse, f. 3 vj Olei terebinthinse, f. 3 iss Tinct. opii camphoratse, f . 3 v Liquoris ammonii acet., f. | iss Syrupi, q. s. ad f. 3 iv M. S. Teaspoonful three times -a day. 38. C,,H,.N03, gr. 14 KI, dr. 2i C3H,0,, oz. li H,0, oz. 2 M. S. Teaspoonful every four hours. 5 39. Potassium chlorate, f ss Fluid hydrastis colorless, f. | ss Carbolic acid, gtt. v Tincture of myrrh, f. | ss Peppermint water, q. s. ad f. 3 iij Mix and label : Gargle. 5 40. Copaibae, Tinct. ferri chlor., Tinct. cantharid., aa. 10 Co. Glycerini, 20 Cc. Syrupi, 50 Cc. M. 41. Camphorae, Chloralis, aa. 5 Gm. Cocainae hydrochloratis, 5 Dg. M. S. To be applied exter- nally as directed. B ^ 42. Chloroformi, Acidi nitrici, Creosoti, aa. f. 3 ij M. S. For cauterizing. 43. Sodii boratis, 3 ij Chloralis, 3 j Alcoholis, f. 3 ss Aquae, q. s. ad f. 3 vj Misce et fiat lotio. 44. Liquor, ferri chloridi, f. 3 ij Potassii chloratis, gr. xxx Glycerini, f. 3 j M. S. Teaspoonful twice a day. n 45. Potassii chloratis, 3 ij Acidi hydrochloric!, f. 3 ij Aquae, f. 3 viij M. S. Gargle. 124 INCOMPATIBILITIES IN PRESCRIPTIONS. B 46. Tinct. cimicifugae, f. 3 vj Tinct. sanguinariae, f. § ss Tinct. lobelise, f. y, iss Syrupi tolutani, f. 3 ij Syrupi scillae co., q. s. ad f. | iij M. S. Tablespoonful every hour until cough is relieved. 47. 15 Iodoform, Tannic acid, Mix and label abraided surface. aa. 3 ij Dust over I^ 48. Ammonii carbonatis, 3 j Hydrarg. chlor. mitis, gr. xij M. Ft. capsulse No. viii. Sig. One every three hours. 49. 15 Potassii cyanidi, 3 j Morphinge acet., gr. ij Acidi acetici, gtt. ij Syrupi, q. s. ad f. $ viij M. S. Cochleare parvum ter in die. 50. B Tincturae ferri chloridi, f. 3 ij Spiritus setheris nitrosi, f. 3 iv Mucilaginis acaciae, f. 3 j Syrupi, q. s. ad f. | iij M. S. Teaspoonful three tiifies a day. n 51. Potassii citratis, Potassii bicarbonatis, Liquoris potassae, Ext. buchu fiuidi, Spiritus setheris nitrosi, Syrupi limonis, q. s. ad M. S. Tablespoonful times a day. 3 vjl 3 iij f. 3ij f. 3vj f. 3iv f- i vj three 52. 5 gr- 3 gr. ss. gr. ss. Bichloride of mercury. Sodium arsenite, Strychnine sulphate. Carbonate of potass.. Dried sulphate of iron, aa. gr. ix Mix and divide into nine pills. Label : One after each meal. 63. 3 Ant] pyrin, gr- XX Calomel, gr . X Sod um bicarb. f 3 j Mix and make 20 powd ers. 54. 3 Sodii salicylatis, 3 iiss- Syrupi limonis, f. | ij M. S. Teaspoonful three times- a day. 55. n 3ij f.!j 3 iss i iss Potassii iodidi, Spiritus aetheris nit., Tinct. ferri chloridi, Tinct. gentianae co., Glycerini, Aquae, q. s. ad f. 3 iv M. S. Teaspoonful three times a day before meals. f. 3 ss INCOMPATIBILITIES IN PRESCRIPTIONS. 125 56. 'H Fowler's solution, f. 3 ij Sol. of dialyzed iron, f. 3 iv Mix. Label : Teaspoonful after meals. 57. 1^ Liq. strychninae, B. P., 1.5 Cc. Sodii bicarbonatis, 3.0 Gm. Aquae, q. s. ad loo.o Cc. Misce et signa : Teaspoonful three times a day. 58. R Liquoris potass, arsenitis, f . 3 j Hydrargyri chloridi cor., gr. j Aquae, f. | iv Misce et fiat sol. Sig. Dessert- spoonful three times a day. 59. n Quininse sulph., gr. x Potassii acetatis, gr. xx Acidi sulphurici dil., gtt. iv Aquae cinnamomi, q. s. ad f . 3 j M." S. Teaspoonful after meals. 60. n Strychninae hydrochlor., gr. j Tinct. cinchonae, f. § j Liq. ferri dialysati, f. 3 ss Liq. potassii arsenitis, f. 3 ij Syrupi, f. 3 iij Aquae, q. s. ad f. 3 vj M. S. Capiat cochleare par- vum post prandium. ^ 61. Quininae sulph., 3 j Morphinae sulph., gr. iij Strychninae sulph., gr. f Acidi arsenosi, gr. 1^ Ext. belladonnae, gr. v Aconitinse, gr. ij Ferri bromidi, 3) M. Ft. pil. No. XXIV. 62. Strychnine sulph., gr. ^ Dil. nitrohydrochlor. acid, 3 ij Water, to make f j Mix. Label : Thirty drops, after meals. B 5 63. Liq. ammonii acet., Syrupi ferri iodidi, aa. f. 3 ss Syrupi tolutani, f. 3 ij Hydrarg. chlor. corrosivi, gr. ss Creosoti, f. 3 ss M. 64. Iodoform i. Acidi carbolici, Zinci oxidi, Balsami peruvi., Petrolati mol., M. S. Apply as directed. gr. XX gr. XXX aa I) 65. 5 Potassium iodide. Fowler's solution, aa. f ss Mix. Take five drops in a little water three times a day. 126 INCOMPATIBILITIES IN PRESCRIPTIONS. ^ 5 66. Carbolic acid, cryst., Euphorin, Aristol, Tannic acid, Dried alum, aa. gr. xl Cacao butter, a sufficient amount Make suppositories No. xl. 67. Quininae sulph., gr. xvj Aquae, f. 3 ij Acidi sulphurici dil., q. s. Ext. glycyrrhizae fl., q. s. ad f. 1 ij M. et ft. mist. 68. Tinct. ferri chlor., f. 3 iv Potassii chloratis, 3 j Glycerini, f. 3 j Ext. glycyrrhizae fl., f. 3 j Aquae, q. s. ad f. 3 iv M. S. One teaspoonful four times a day. I^ 69. Ferri reducti, 3. o Gm. Acidi arsenosi, 0.35 Gm. Quininae sulph., 8. o Gm. Strychninae sulph., 0.35 Gm. Extract; gentianae, 8. o Gm. M. Ft. pil. No. XL. 70. Acidi carbolici, 3 iss Aquae, q. s. ad ^ j M. S. Use with camel-hair brush. 71. 3 Liq. ammonii acet., Acidi acetici, Tinct. ferri chlor., Glycerini, Mucilaginis acaciae, M. S. Teaspoonful three hours. f. |iv f.3j f. 1 ss f. 3 ss f- 3 iij every 72. 5 Hydrarg. chlor. cor., Muc. acaciae, gr- iij Aquae, Liquoris calcis, M. aa. 3 ij 73. I^ Syrupi acidi hydriodici, f. 3 ij Bismuthi subnit., 3 iss M. S. Teaspoonful three times a day. 3 74. Sodii bicarbonatis, 3 ij Pepsini, gr. xxiv Sodii bromidi, 3 j Rhei pulv., gr. xxxij M. Ft. chart. No. xii. 75. Sodii phosphatis, gr. xxx Strychninae sulph., gr. ss Syr. aurantii corticis, 3 ij M. S. Teaspoonful three times a day. 5 76. Alcohol, 30 Cc. Iodine, 10 Gm. Turpentine, 200 Cc. Mix. To be used as a spray. INCOMPATIBILITIES IN PRESCRIPTIONS. 127 77. n Hall's sol. of strych., f. 3 ij Fowler's sol. of arsenic, f. 3 ij Alcohol, f. 1 iiss Mix. Label : Teaspoonful in half glass of water after meals. 78. n Tinct. myrrh^e, Morph. acetatis, Acidi tannici, Syr. zingiberis, Misce et fiat sol. Sig. Teaspoonful at 6, 8, and 10 o'clock P.M. f. 3ij gr- ij 3 ss I iss 79. ^ Hydrargyri chlor. cor., .5 Gm. Ammonii carbonatis, 2.5 Gm. Potassii iodidi, 2.5 Gm. Aquas, q. s. ad 150 Cc. M. S. Dilute with three times its volume of water and use as directed. 80. n Potassii chloratis, 3 ij Syi'. ferri iodidi, f. 3 ij Vini antimonii, f. 3 ss Spt. chloroformi, f. 3 ij Aquae, q. s. ad f. § viij M. S. Teaspoonful three times a day. ^ 81. Liq. ammonii acetatis, f. § ij Aq. camphorae, f. 3 iss Spiritus astheris nit., f. 3 ss Antimonii et pot. tart., gr. ss Morphinae acetatis, gr. ss M. I^ n 82. Potassii chloratis, i.o Gm. Potassii salicylatis, 0.5 Gm. Cinchona pulv., 3.0 Gm. Carbonis ligni, 5 o Gm. M. Divide into 10 powders. S. One just after a meal. 83. Calcii hypophosphitis, 2.5 Gm. Ferri lactatis, .3 Gm. Potassii chloratis, 4.0 Gm. M. Ft. pil. No. XXX. 84. I^ 3ij Iodine, resublimed, Mercurial oint., Camphor, aa. 3 iij Alcohol, f. 3 ij Water, q. s. ad f. 3 iv Mix and label : Apply as oint- ment to the neck. 85. Boric acid, 3 iv Creolin, 3j Water, 3 xv Mix and label : Lotion for the eye. 86. Magnesii carbon., 3 iss- Sodii boratis, Acidi citrici, aa. 3 ij Aquae bullientis, q. s. ad f. 3 viij M. S. Tablespoonful in the. morning before breakfast. 87. Auri et sodii chloridi, gr. xij Strychninae sulph., gr. j Atropinae sulphatis, gr. I Ext. cinchonae fl., f. 3 iij Aquae, q. s. ad f. 3 v| M. Ft. sol. 128 INCOMPATIBILITIES IN PRESCRIPTIONS. 88. 3 ti Morphinae sulph., gr. iv Atropinae sulph., 32 (1-500 gr.) tablets Aquae, f iv M. S. Teaspoonful every three jf-juarters of an hour. 89. Potassii permanganatis, gr. xx iExt. glycyrrhizae, gr. xx Tinct. opii, gtt. xx. Zinci acetatis, 3 j Syrupi, q. s. ad f. 3 iiJ! M. S. Teaspoonful every three hours until relieved. 230. n Ergotin, gr. x Tinct. of cinnamon, 3 j Mix and label : Take as di- rected. 231. n Plumbi acetatis, Ammonii carbonatis, aa. 3 }' Aquas rosae. f. 1 vii) Fiat lotio. Signa : Apply on. lint to allay irritation. n 232. Ergotinse, Apioli, Olei sabinae. Mix and make 18 pills. gr. XX 3 iss 3 ss INCOMPATIBILITIES IN PRESCRIPTIONS. 141 B 233. Sodii salicylatis, 3 ij Quininae sulph., gr. xxiv Hydrargyri chlor. cor., gr. f Liq. potassii arsenitis, TTl, xlviij Elixiris aromatici, q. s. ad f. 3 iij M. 234. Fl. ext. Hydrastis colorless, f. 3 j Sodium bicarbonate, Bismuth subnitrate, aa. 3 ss Borax, 3 ij Honey, § ss Peppermint water, enough to make 3 vj Mix. Label : Shake well. Teaspoonful before meals. 235. Iodine, gr. xxx Compound camphor lin., f. 3 iij Soap liniment, enough to make f. 3 ij Mix. Label: Apply as directed. 236. Acidi carbolici, 3 iij AqucB ammonise, Liq. sod. chloratae, aa. 3 ij Aquae, q. s. ad f. 3 viij M. S. Lotion. ^ 237. Ext. henbane, gr. xvj Ext. cannabis ind. gr. xvj Chloral hydrate, 3 ivss Potassium bromide, 3 ivss Alcohol, 3 j Water, to make 3 xvi Mix. Label : Teaspoonful at night. n 238. Calomel, gr. x Sodium bicarb., gr. xx Sugar, powd., gr. xl Mix and make 40 powders. 239. ^ Sodii bicarbonatis, 3 ij Sodii salicylatis, 3 iv Chloroformi, 3 ss Acidi carboHci, TTl x Aquae fontanae, q. s. ad 3 iv M. S. Teaspoonful one hour after meals. 3 240. Antipyrin, Acetanilid, Resorcin, Water, Mix. Label aa. 2 Gm. 3 Gm. 100 Cc. Teaspoonful every hour until the fever begins to subside. 241. n Cocaine hydrochlor., 0.8 Gm. Flexible collodion, 10. o Gm. Mix. Apply with camel-hair brush. 242. I^ Atropine sulphate, gr. ij' Olive oil, 3 ij Mix. Label : Apply with fric- tion. ^ 243. Chromic acid, gr. iv Cocaine hydrochlorate, gr. vj Water, 3 i; Mix. Use as caustic. ^ 244. 1^ Sp. aetheris nitrosi, Tincturae guaiaci, aa. f . 3 j Tincturae colchici, f. 3 iv Syrupi, f. 3 iij; M. 142 INCOMPATIBILITIES IN PRESCRIPTIONS. ^ 245. Zinci sulphatis,' Pot. sulphurate, aa. gr. xxx Aquae rosae, 3 vj Mix. Label : Lotion. 246. 3 gr. I B Strychnine sulph., Arsenous acid, -Mass carb. of iron, gr. 1 :SuIphuric acid aromat., gtt. iij •Quinine sulphate, gr. xx iMix and divide into 20 pills. 247. Silver nitrate, gr. x Potassium permanganate, gr. xv Distilled water, 3 ij Mix. Use as wash. 248. Guaiacol carbonate, gr. uj Thymol, gr. j Menthol, gr. ss Eucalyptol, ""1 v For one capsule. Send 20 such. 249. Benzoic acid, Salicylic acid, aa. gr. iij Cocaine hydrochlorate, gr.^v Distilled water, 1 j Mix and make solution by aid of water-bath. Label : Apply locally. 250. Antikamnia, 3j Strychnine sulph., gr. j Iron sulphate, dried, gr. iij Quinine sulphate, 3 j Mix and put into 9 capsules. Label : One every night and morning. 251. ^ Oil of cinnamon, gtt. x Chloroform, Tincture of opium, Spirit of camphor, Aromat. spirit of ammonia, aa. f. 3 V Whiskey, 3 iss Mix. Dose : One dram as needed. 252. I^ Argenti nitratis, gr. vj Liquoris Fowleri, f. 3 j Aquae, q. s. ad f. 3 iv M. S. Teaspoonful twice a dav. ^ 5 253. Hydrarg. iodidi viridis, gr. f Potassii chloratis, gr. iij Potassii iodidi, gr. f Chocolate, a sufficient amount. Mix. Make one tablet. Send 20. 254. Olei ricini, Glycerini, aa. 20 Cc. M. S. Tablespoonful at night. 256. Volatile liniment, | iss Tincture aconite, 3 ij Tincture iodine, 3 ij Mix. Apply as directed. 256. Unguenti hydrargyri, 3 v Tincturae iodi, f. 1 iij Mix well and make an oint- ment. Label: Apply as directed. 3 INCOMPATIBILITIES IN PRESCRIPTIONS. 143 257. ^ Syr. ferri iodidi, f. § j Antipyrini, 3 ij Syrupi, f. 3 j M. S. Teaspoonful as di- rected. 5 5 258. Acidi carbolici, 3 j Potassii pernianganatis, gr. xx Aquae, f • 3 v M. S. Lotion. 259. Plumbi acetatis, Boracis, aa. i Gm, Glycerini, 20 Cc. Aquas, 80 Cc. M. S. Apply as directed. 260. Acidi tannici, gr. xv Tincturae iodi, f. 3 j Glycerini, f. 3 ij Aquae, f . 3 v M. S. Apply twice a day. 261. Potassii chloratis, 3 j Acidi sulphurosi, 3 iv Glycerini, 3 iij Aquae, 1 j M. S. Mix one teaspoonful with a glass of water and use as a gargle. ^ 5 262. Acidi chromjci, Glycerini, Alcoliolis, M. S. Caustic. SGm. aa. 5 Cc. 263 5 Ammoniated mercury, 3 ss Tincture of iodine, 3 ss Lard, 3 j Mix and make an ointment. 264. Salol, gr. XXX Tincture chlor. of iron, f. 3 ij Syrup, enough to make f. 3 iij M. S. Teaspoonful three times a day. 265. Tinct. of iodine, f. 3 ij Collodion, f. 3 iij Ammonia water, f . 3 ; Mix. Apply with camel-hair brush. 266. ^ . . . Liq. iodi comp., f. 3 ij Liq. potass^, f. 3 iv Olei olivae, f. 3 y M. S. Apply as directed. 267. 5 . Tinct. chloride of iron, f. 3 j Sol. of arsenous acid, f. 3 ss Quinine sulphate, gr. x Cinnamon water, f. ~ i) Mix. Label : Teaspoonful three times a day. 268. Pyrogallic acid, gr. v Mercuric chloride, gr. ss Lard, 3 j Mix and make an ointment. 269. Exalgin, gr. iv Beta-napthol, gr. xij Lard, 3 iv iMix. 144 INCOMPATIBILITIES IN PRESCRIPTIONS. 270. ^ Olei tiglii, gtt. ij Glycerini, f. 3 j M. S. Take in two doses four hours apart. ^ gr. X gr. V 271. Plumbi acetatis, Acidi pyrogallici, Aquae, M. S. Lotion. 272. Olei morrhuse, f. 3 iv Acaciae, 3 j Syrupi tolutani, f. 3 iv Sodii boratis, gr. xv Aquae, q. s. ad f. 3 ij M. S. Teaspoonful three times a day. 273. B Strychninae sulph., Potassii cyanidi, aa. gr. ss Aquae, q. s. ad f. 3 ij M. S. Teaspoonful night and morning. ^ 3 iij 3 ss 3 iij 274. Glycerini, Sodii boratis, Unguenti, M. S. Apply at night. 275. Mercuric chloride, gr. j Tartar emetic, gr. v Syrup of squills, f. 3 ij Mix and label : Half teaspoon- ful as directed. 276. ^ Morphine hydrochlor., gr. iss Codeine, gr. iij Ammonium chloride, gr. xx Water, enough to make f. % ij Mix and label : Teaspoonful every two hours for cough. ^ 277. Calcis calcinatae, Sulphuris, Aquae, 3ij 3 iij f. !iv Mix and boil for ten minutes and then filter. Label : Use as directed. n ^ 278. Zinci oxidi, 3 ij Glycerini, f. 3 ij Liq. plumbi subacetatis, f . 3 j Liquoris calcis, q. s. ad f. 3 iv M. S. Lotion. 279. Calcis chloratae, Glycerini, aa. 10 Gm. M. S. Apply as directed. 280. n 3j Acetate of potassium. Divide into 6 powders. Label : Take one every two hours. 3 281. Acidi salicylici, gr. x Potassii permangan., gr. xv Ferri sulphatis, 3 iv Aquas, q. s. ad f. 3 viij M. S. Lotion for ulcer. INCOMPATIBILITIES IN PRESCRIPTIONS. U5 282. T^ Quininae sulphatis, 3 ss Tinct. ferri chlor., f. 3 ij Syrupi zingiberis, f. § ij Tinct. guaiaci amnion., f. | j M. S. Teaspoonful twice a day. 3 B ^ 283. Quininae sulph., Potassii permangan., Ferri reducti, aa. gr. x Misce. Fiant pilulse No. x. Sig. Pil. j ter in die. 284. Strychninae, gr. j Glycerini, TTl, xxx Aquae, q. s. ad f. 3 iij M. S. Inject ten minims. 285. Acidi carbolici cryst., gr. xxx Thymol, gr. x Vaselini, Cerati, aa. 3 j M. S. Unguentum. B 286. Sodii phosphatis, | ij Sodii chloridi, 3 iv Lithii bromidi, 3 iij Aquae, q. s. f. 3 viij M. Ft. Sol. Sig. Take dessertspoonful three times a day. B *"• Quinine sulph., gr. 1 Podophyllin, gr. iv Tinct. chlor. of iron, f. 3 iiss Tinct. of rhubarb, f. 3 iss Mix. 288. Powdered camphor, gr. Ixx Lead acetate, gr. 1 Tinct. of iodine, TTL 1 Carbolic acid, gr. xx Mix and make 24 pills. 289. Quininae sulphatis, gr. xx Potassii iodidi, 3 ij Acidi citrici, gr. xx Aquae, f_. 3 ij M. S. Teaspoonful three times a day. 290. Phenacetin, gr. xv Tincture ferric chloride, f. 3 ij Water, enough to make f. 3 ij Mix and label : Teaspoonful twice a day. 291. Sodium salicylate. Sodium benzoate, aa. 3 j Tannic acid, gr. x Carbolic acid, gtt. xij Lime water, f. 3 iv Mix. Label: Teaspoonful half hour after meals. 292. U . Bichloride of mercury, gr. x Spirit of nitrous ether. Dilute alcohol, of each f . 3 j Mix. Label: Apply externally. 293. I^ Potassii chloratis, 3 i Aquae bullient., f. 3 j Liq. morph. hydrochlor., B. P., Syrupi tolutani, f. 3 ij M. S. Teaspoonful when coughing. 146 INCOMPATIBILITIES IN PRESCRIPTIONS. 294. n Syrupi acidi hydriodici, f. 3 vj Ext. cinchonae fl., f. 3 j Liq. hydrarg. chlor. cor. (1-500), f. 3 ij Syrupi, f. 3 vij Misce et signa : Teaspoonful every four hours. 295. ^ Tincture chloride of iron, f. 5 j Dilute phosphoric acid, f. § j Syrup of hypophosphites, f. I viij Mix. Label: Teaspoonful after meals. 299. I^ 296. Syr. ferri iodidi, f. 3 jv Syr. hypophosphitum, f. 3 j Quininae sulph., 3 j Acidi phosphorici dil., f. 3 iij M. 297. Calcii hypophosphitis, 3 j Aquae, f. 1 ij Tinct. ferri chlor., f. 3 iv Morph. sulphatis, gr. iv Syrupi tolutani, f. 3 ij M. S. Teaspoonful three times a day. I^ 298. Hydrargyri chlor. cor., gr. iv Sodii arsenatis, gr. iiss Strychninae sulph., gr. i Potassii carbonatis, Ferri sulph. exsic, aa. gr. x Misce et fiant pilulae No. x. ^ Calomel, 3 ij' Soap, 3 ij Cotton-seed oil, f • 1 > Water, f. 3 j Mix. Label : Apply with fric- tion. 300. ^ Liq. sodii arsenatis, 3 ij) Potassii iodidi, gr. xl Quininae sulph., 3 j Acidi sulph. dil., f . 3 j Aqus, q. s. ad f. 3 iij M. S. Teaspoonful twice a day. 301. Balsami Peruviani, 4 Gm. Ext. glycyrrhizae, q. s. Misce. Make 10 pills. Signa : One night and morn- ing. 302. Acidi hyd. dil., 20 Cc. Aquae, 100 Cc. M. Sig. Teaspoonful in water after meals. 303. Petrolatum, 30 Gm. Oxide of zinc, 4 Gm. Glycerin, 5 Gm. Gum tragacanth, 5 Gm. Mix and make ointmenv. Label : Apply as directed. ^ 304. Potassii iodidi, 2 Gm. Divide into 12 powders. Take one dissolved in water at night. INCOMPATIBILITIES IN PRESCRIPTIONS. HT 305. B lodi resublim., gr. xl Adipis, 3 j M. S. Rub over the affected part. 306. Potass, chloratis, 3 ij Syr. ferri iodidi, | ss Quininae sulph., 3j Ac. sulphurici dil., fTl xx Aquae, q. s. ad 3 ij M. S. Teaspoonful after each meal. 307. Tincture of aconite, ^, xx Phenacetin, gr. xl Spirit of nitrous ether, |f. 3 v Syrup, f. 3 iij Water f. 3 ij Mix and label : Teaspoonful every two hours until the fever subsides. 308. Bals. copaibae, Pulv. cubebse, aa. 3 j Misce et fiant pilulae No. xx. Signa : One night and morn- ing. 309. Bismuthi subnit., 3 j Sodii salicylatis, 3 j Aquae cinnamomi, 1 ij M. S. Shake well ! Teaspoon- ful twice a day. n 310. Chloral hydrate, 3 j Phenacetin, gr. xl Quinine sulphate, gr. 1 Mix and put into 10 capsules, Label: Take one at night. n 311. Aloin, gr. ij Salol, gr. xl Tinct. of hyoscyamus, 3 iss Ext. of jalap, gr. x Strychnine sulph., gr. 5 Mix and make 20 pills. Label : Take one at night. 312. ^ . . . Salicylic acid, gr. xx Glycerin, f. 3 j Lime water, f • 3 v Mix. Label: Tablespoonful: twice a day. n 313. Acetanilid, 3 ij. Tinct. of ferric chloride, f . 3 v Water, enough to make f. 3 iv Make solution with the aid of heat. Label : Teaspoonful three times a day. 3 314. Potassii bichromatis, gr. x Ferri sulphatis, 3 iss Aq. hydrogenii dioxidi, Glycerini, aa. f. 3 j Aquae dest., q. s. ad f. 3 iv M. S. Lotion. 315 Iodoform, gr. xxx Boric acid, 3 j; Calomel, gr. xx Bismuth subnitrate, 3 j. Mix. Label: Dust on abraid- ed surface as directed. 148 INCOMPATIBILITIES IN PRESCRIPTIONS. 3 316. Glyc. boroglycerini, | j Hydrargyri chlor. cor., gr. ij Aqu?e, q. s. ad 3 iv M. S. Apply to ulcer. 1^ 317. Tinct. iodi comp., f. 3 ij Acidi salicylici, 3 j Glycerini, f. | iss Aqute, enough to make f. 3 iv. Mix and label: Paint over the •affected part several times a day. 318. B Citrate of iron and quin., 3 iiss Carbolic acid, Tinct. of lavender co., aa. 3 ss Wine, enough to make ^ iv Mix. Label: Teaspoonful three times a day. 319. B Diuretin, gr. x Sp. of nitrous ether, TTl, xxx Tinct. chlor. of iron, 3 iv Syrup, enough to make f. ^ ij Mix. Label: Teaspoonful three times a day. 3 320. Quinine sulph., gr. x Antipyrin, gr. x Chloral hydrate, gr. xx Mix and put into 8 capsules. Label : One every two hours. 5 321. Pilocarpine, gr- j Terpin hydrate. 3j Glycerin, f.3ij Syrup of tolu, f. 1 iss Water, f. 3 iss Mix and make a solution. Teaspoonful five times a day. 322. Syr. ferri iodidi, f. 3 iss Potass, iodidi, 3 j Potass, bicarbon., 3 j Syr. tolutani, f. 3 ss Aquse, f. 3 ij M. S. Teaspoonful three times a day. 323. Acetanilid, gr. v Phenacetin, gr. x Pyrocatechin, gr. x Mix and put into 10 capsules. Label : One every four hours. 324. 5 ^1 3ij gj- j f. 3 ss f.3ii f._ 3 Jv times Quininse sulph., Ferri phosphatis sol., Strychninse sulph., Acidi phosphorici dil., Syrupi zingiberis, Aquae, q. s. ad M. S. Teaspoonful three a day. 325. Ferri et potass, tartratis, 3 ss Potassii iodidi, 3 ss Quininae sulphatis, gr. xv Acidi sulphurici dil., fTL xx Syrupi, f. 3 ss Aquae, q. s. ad f. 3 ij M. S. Teaspoonful twice a day. INCOMPATIBILITIES IN PRESCRIPTIONS. 149 326. B Quinine sulphate, 3 j Strychnine sulphate, gr. j Phosphoric acid dil., f. 3 iv Tinct. chloride of iron, f . 3 v Aromatic elixir, to make f. 3 iv Mix. Label : Take a teaspoon- ful after meals. 327. Hydrargyri, gr. \ lodi, gr. I Acidi tannici, gr. |- Glycerini, Tr|, xv M. S. One half by hypoder- mic injection. 328. Tincturae iodi, f. 3 iij Liquoris potass, arsenitis, f 3 ij M. S. Take five minims in water after meals. 329. Calomel, gr. ij Pepsin, gr. xx Sodium bromide, gr. xl Mix and make four powders. Label : Take one every hour. 330. Sol. strych. hydrochlor., f. 3 iij Sol. of saccharin, to make f. 3 ij Mix. Label : Twenty drops three times a day. 331. Boroglycerin, 50^, 3 iv Vaselin, 3 iv Mix. Label : Apply freely. 332. Infusi humuli, f. § vj Tincturse iodi, f . 3 j Glycerini, f. | j Mix. Use as directed. R 333. Tinct. myrrh, f. 3 iv Tinct. chloride of iron, f. 3 j Glycerin, f. 3 iij Sat. sol. potass, chlorate, f. 1 ij Mix. Label: Use as gargle. 334. B m xl 3 iss ss Fl. ext. nux vomica, Fl. ext. digitalis, Tinct. strophanthus. Potassium nitrite, 3 viss El. gen. andiron, to make 3 vj Mix. Label: Teaspoonful three times a day. 335. ^ ^ Oil of cubebs, f. 3 iij Oil of sandalwood, f. 3 iv Balsam of copaiba, f, | j Sp. of nit. ether, to make | iv Mix. Label: Teaspoonful three times a day. 336. Potassii chloratis, 3 j Tincturge ferri chloridi, f. "^ j Acidi carbolici, gtt. x Aquae, q. s. ad f. f ^' M. S. Use as gargle. 337. Oleate of mercury, 2^, | j Iodine, gr. ij M. Label: Use locally. 338. ^ .. . . Potassii citratis, 3 ij Potassii chloratis, 3 iiss Spiritus aetheris nitrosi, f . | j Aquas camphorae, f. 3 vj M. S. Dessertspoonful every two or three hours. B ISO INCOMPATIBILITIES IN PRESCRIPTIONS. B 339. Argenti nitratis, 3 j Glycerini, f. 3 ij Aquse dist., f. 3 j Mix and mark No. i. Label: Mix three drops with six drops of No. 2 and put into eyes at bedtime. Potassii iodidi, 3 ij Glycerini, f. 3 iv Aquae dist., f. 3 ij Mix and mark No. 2. Label: Mix six drops with three drops of No. i and put into eyes at bedtime. 340. ^ Morphinje sulph., gr. j Chloroformi, 3 ss Spir. ammoniae aromat., 3 ij Aquae camphorae, q. s. ad 5 j M. S. Teaspoonful when needed for pain. 343. 341. ^ Spts. turpentine, f. 5 iiss Mercuric chloride, 3 ss Mix and make solution. Iodine, 3 ss Alcohol, f. 3 iiss Dissolve iodine in alcohol and add to above solution. Label : Liniment. 3 342. Sodium bromide, 3 iv Antipyrin, 3 iss Chloral hydrate, 3 iiss Syrup lemon, f. 3 j Water, to make f. | iv Mix. Label : Teaspoonful at bedtime. ^ Piperazin, 3 } Strychnine sulphate, gr. ij Syrup orange, f. 3 vj Chloroform water, to make f. ~ vj Mix. Teaspoonful three times aday. g^^^ Chloral hydrate, Ammonol, of each gr. xxv Mix and make five capsules. Label : One every four hours. 345. Antipyrin, gr. x Quinine sulphate, gr. j Dil. sulphuric acid, q. s. Cinnamon water, to make f ■ 3 j Mix. Take in two doses one hour apart. 346. Calomel, gr. j Salol, gr. XX Trional, gr. x Make capsules No. 6. Label : One every hour. 347. Sodium bromide, gr. xl' Antipyrin, gr. xxxvj Camphor, gr. iv Caffeine citrate, gr. vj Tinct. aconite, gtt. xij Mix and make twelve capsules. Label: One capsule every three or four hours. 348. Guaiacol, 3 \y Acacia, 3 ij Amnion, carbonate, 3 ii> Infusion digitalis, f. 3 iss Water, to make f. 3 iij Mix. Label : Teaspoonful four times a day. INCOMPATIBILITIES IN PRESCRIPTIONS. 151 349. 3 Gold and sodium chlor., gr. ss Strychnine sulphate, gr. j Alcohol, f. 1 j Syrup cinnamon, f. ^ ij Water, to make f. | vj M. Take one teaspoonful in water after each meal. 360. 3 Potass, acetatis, 3 ss Spiritus aetheris nit., f. 3 ij Aquae, q. s. ad f. 3 j M. S. Take in two doses ■one hour apart. B 351. Mercury protiodide, gr. xvj Potassium iodide, § iij Water, | iij Mix and make solution. Label : One half teaspoonful three times daily. 352. Morphine sulphate, gr. j Antikamnia, gr. xx Elixir aromatic, f. ^ j Mix and label : Teaspoonful at bedtime. 353. Fl. ext. epigsea repens, f. 3 ij Fl. ext. uva ursi, f. 3 iss Spirit of nitrous ether, f. 3 ss Label : Take a teaspoonful ■every two or three hours. 354. 3 Tincturae iodi, Olei terebinthinse, aa. f. § ss M. S. Shake and apply lo- cally to spine night and morn- ing. ^ 3iv !ij 355. Potassii chloratis, Sacchari albi, M. Ft. pulv. Sig. As directed. 356. Corros. chlor. mercury, gr. j Iodide of potass., 3 ij Mur. tinct. iron, f. 3 ss Syr. sarsaparilla, f. 3 iss Ess. of pepsin, to make f. 3 iv Mix. Label : Teaspoonful in one half glass of water, after eating. 357. Benzoic acid, 3 ij Borax, 3 iss Syrup, f.^3 j Water, to make f. 3 iv Mix. Label : Dessertspoon- ful in water every three or four hours. 358. Potassii chloratis, 3 ij Syrupi ferri iodidi, f. 3 ss Syrupi, q. s. ad f. 3 iv M. S. Thirty drops in a tum- bler of water. Use as gargle. 359. ^ Magendie's solution of morphine, f. 3 ij Sat. solut. potass, iodide, f. 3 vj Label : Take ten drops three times a day. B 360. Powd. borax, 3 ij Tinct. myrrh, f. 3 ij Water, to make f. 3 ij Mix. Label : As directed. 152 INCOMPATIBILITIES IN PRESCRIPTIONS. 361. n Calcii hypophosphitis, 3 x Potass, hypophosphitis, 3 viij Sodii hypophosphitis, 3 x Ferri lactatis, gr. iij Strychninai lactatis, gr. iss Acidi lactici, f. 3 vj Elix. gentianae et tinct. ferri chloridi, f. 1 viij Aquae, q. s. ad f. I xvj M. Ft. solut. S. Teaspoonful three times a day. 362. Strychnine sulph., gr. j Fowler's solution, 3 ij Iron and quinine citrate, 3 iv Glycerin, 3 iv Cinnamon water, to make 3 viij Mix. Label : One teaspoon- ful after meals. 363. Bismuth subnitrate, 3 j Ess. cinnamon, f. 3 ss Glycerin, f. 3 ss Carbolic acid, gtt. xxx Lime water, f. 3 iij Mix. Label : Shake before using. One teaspoonful in a tablespoonful of water just before meals. 364. Argenti nitratis, gr. ij Glycerini, f. 3 iv Aquae, f. 3 iv M. S. One drop in each eye at night. 365. Fl. ext. ergot, Tr. chlor. iron, aa. f. 3 vj Tr. nux vomica, f. 3 iv M. L. Take thirty-five drops three times a day. 366. ^ Sp. aetheris nitrosi, f. 3 viij Ext. digitalis fl., f • 3 j Mix. Label : Two tablespoon- fuls a day. 367. Sod. salicylatis, 3 } Pot. iodidi, 3 ss Pot. citratis, 3 j Sulphonal, 3 ss Mix and make twelve pills. Label : One every three hours. 368. Po. opium, gr. xxv Silver nitrate, gr. xiiss Mix and make fifty capsules. Label : Take as before. 369. Potass, iodidi, 3 iij Strych. sulphatis, gr. j Liq. potass, arsenitis, f. 3 iiss Aquae amygd. am., q.s.ad f. 3 iv M. S. Teaspoonful four times daily. 370. Tr. capsici, f . 3 j Acidi carbolici, lU xx Bismuthi subnit., 3 v Alcoholis, f. 3 ij Olei gaultheriae, f . 3 j Spir. amnion, aromat., f. 3 iv Aquae, f. 3 ij Misce. Signa : Take one half teaspoonful as directed. 371. Antipyrin, 3 iiss Caffeine, 3 ij Sod. bromide, 3 vj Syrup of lemon, f. 3 iss Cinnamon water, to make f. 3 iv Mix. Label: Teaspoonful as needed. INCOMPATIBILITIES IN PRESCRIPTIONS. 153 372. B Citrated caffeine, 2.0 Gms. Spirit nitrous ether, 20.0 Cc. Basham's mixture, 100. o Cc. Mix. Label : Dessertspoon- ful three times a day. 373. Acidi carbolici, 3 j Tr. iodi, 3 ij Acidi tannici, 3 j Cerati, § iv Misce. Signa : Ointment. 374. Sol. of ammon. acetate, f. 3 ss Spir. of nitrous ether, f. 3 ss M. L. Teaspoonful every two hours. 375. Potass, iodide, 3 ij Potass, bromide, 3 vj Quinine sulphate, gr. xxxvj Dil. sulphuric acid, 3 j Tinct. of orange peel, 3 vj Water, to make 3 vj Mix. Label: Teaspoonful after meals. 376. ^ .. . . Sodii salicylatis, 3 iij Quininse sulphatis, gr. xvj Tinct. podophylli, f. 3 ij Spir. setheris nitrosi, f. 3 iv Aquae camphorse, f. 3 vj M. S. Dessertspoonful twice a day. 377. Atropine sulphate, gr. iss Strychnine sulphate, gr. iij Salicylic acid, gr. v Borax, gr. v Water, to make 3 ij Mix. Label: Teaspoonful twice a day. 378. 5 Tinct. of aconite, gtt. xx Spir. of nitrous ether, f. 3 j Morphine sulphate, gr. f Sol.of pot. citrate, to make f. 3 ij M. L. Dessertspoonful in water every hour. 379. n Citrate of potassium, 3 ) Divide into sixteen powders. Label : One powder in water four times a day. n 380. Carbolic acid, gtt. x Monsel's solution, f. 3 iij Glycerin, to make f . 3 j Mix. Use as gargle. 381. n Chlor. of gold and sod., gr. xij Ammonium muriate, gr. vj Strychnine nitrate, gr. J Atropine sulphate, gr. ^ Fl. ext. of cinchona, f. 3 iij Fl. ext. of coca, f- 3 j Water, Glycerin, of each f. 3 j M. L. One teaspoonful every two hours. n 382. Borax, 3 j Alum, 3 j Glycerin, f . 3 j Rose water, to make f. 3 viij Make solution. Label: Lotion. 154 INCOMPATIBILITIES IN PRESCRIPTIONS. 383. ^ Liq. ferri dialysati, f. | j Tinct. lavendulfe co., f. 3 iv Tinct. gentianae co., f. 3 iv Bismuthi subnitratis, f. 3 iij Elix. lactopeptin, q. s. ad f. 3 iv M. S. Shake well and take one teaspoonful after each meal. 384. Chloral hydrate, Camphor, of each 3 j Starch, 3 j Mix. Label : Rub on as di- rected. 385. Quininse sulphatis, 3 j Acidi sulphurici aromat.,Tri,xxx Spin ammoniac aromat., f. 3 ss Syr. sarsaparillse co., f. 3 ivss M. S. Dessertspoonful three times a day. 386. Phosphorus, gr. \ Strychnine sulphate, gr. f Soluble phosphate iron, 3 iv Detan. elixir cinchona, f. 3 ij Mix. Label: Teaspoonful three times a day. B 387. Tinct. nucis vomicae, f. 3 ss Syr. ferri iodidi, f. 5 j Quininae sulphatis, 3 j Glycerini, f. 3 ij Aquae, q. s. ad f. 3 iv M. S. Teaspoonful after meals. R 388. Mercuric chloride, gr. j Tartar emetic, gr. j Morph. hydrochloride, gr. iij Aromat. spirit of ammon., f . 3 v Syrup of liquorice, 3 iij Mix. Label : Teaspoonful when coughing. 3 389. Hydrarg. chlor. corros., gr. iij Zinci sulphocarbol., gr. iv Morphinae sulph., gr. ij Aquae hydrogenii dioxidi, f. 3 j Aquae ros^e, q. s. ad f. 3 vj M. S. Use as directed three times a day. 390. Liquoris sodii arsenatis, f. 3 j Syrupi ferri iodidi, f. 3 vij M. S. One half teaspoonful in water three times a day. 39L B Tannic acid, 3 ij Tinct. of iodine, 111 Ixxx Potassium iodide, gr. xx Tinct. of myrrh, lU Ixxx Rose water, to make f. 3 viij Mix. Label : Dessertspoonful in water as mouth wash. 392. Peroxide of hydrogen, Glycerin, of each f. 3 iss Mix. Label : Gargle freely. 393. 5 Sodium salicylate, 3 iss Caffeine citrate, gr. xx Phenazonum, 3 j Syrup of orange, f. 3 iij Water, to make f. 3 iv M. L. Teaspoonful three times daily. 394. Ammonii chloridi, Sodii salicylatis, aa. 3 ij Syrupi Tolutani, 3 vj Aquae, q. s. ad 3 ij M. S. Teaspoonful four times a day. INCOMPATIBILITIES IN PRESCRIPTIONS. 155 395. B Quininae sulph., gr. xl Sodii salicylatis, gr. 1 Trional, 3 ss M. Ft. pil. No. 10. S. Take one three times a ■day. 396. 3 Mercuric chloride, gr. j Fowler's solution, gtt. xlviij Syrup iodide of iron, 3 vj Elixir of cinchona, to make 3 vj Mix. Label: Teaspoonful after meals. 397. n Ext. suprarenal gland (scale) 3 ss Make powders No. 20. Label : One every three hours. 398. n Phenacetin, gr. xxiv Syrup, 5 j Water, ? iij Mix. Label : Teaspoonful every hour until temperature is lowered. 399. Quininae sulphatis, Ammonii valerian., aa. gr. xxx M. Ft. pil. No. 10. Sig. One three times a day. 400. Menthol, gr. xx Chloroform, 3 j Tinct. benzoin, 3 iss Liquid albolene, | j Mix and Label : Spray the throat every four hours. CRITICISMS. 1. When solutions of the first two ingredients are mixed together the insoluble mercuric iodide is formed, and this is redissolved in excess of potassium iodide, forming potassium mercuric iodide, or, as it is commonly known, Mayer's reagent. This compound precipitates the alkaloids of cin- chona in the elixir. The alcohol in the elixir is a solvent for this precipitate, but upon addition of the syrup the alcohol is too dilute to exercise much of a solvent effect. The syrup of rhubarb is generally turbid, and it will also cause a pre- cipitation of some of the matter from the elixir of cinchona. The danger in such a prescription is that the patient may take most of the precipitate at one time and thereby get an overdose of the mercuric iodide, which is thrown out of solu- tion with the alkaloids. In 4 fluid ounces of the elixir of cinchona there should be 2.8 grains of total alkaloids. This amount of alkaloids will precipitate about 4 grains of mercuric iodide. In this prescription most of the mercury will be precipitated. It should be dispensed with a " Shake well " label. 2. There is enough of ammonium carbonate present to neutralize all of the sulphuric acid and liberate the free alkaloid. The quinine sulphate should be dissolved in part of the syrup with the aid of the acid, and the carbonate in the remainder of the syrup. These two solutions should be cooled thoroughly before mixing, because when warm the 156 INCOMPATIBILITIES IN PRESCRIPTIONS. 157 free alkaloid collects in sticky masses and it is impossible to get it evenly divided. The effervescence is due to the libera- tion of carbon dioxide by the acid. 3. If the ingredients are powdered separately and then mixed lightly together there will probably be no danger of explosion, and no chemical reaction will take place while the powder is dry. But when taken into the stomach the potas- sium chlorate with the hydrochloric acid of the gastric juice will undoubtedly oxidize the calomel, forming mercuric chloride. When one of the above powders was mixed with two ounces of water containing four per cent, of hydrochloric acid and the mixture allowed to stand for some time tests for mercuric chloride could be obtained. The reaction would have taken place much more quickly at the temperature of the body. Although this may be considered a rather dan- gerous prescription it has been filled and taken without ap- parent ill effect. 4. Chemical reaction takes place between the ammonium car- bonate and the acetic acid of the syrup of squills, liberating carbon dioxide. Care must be taken not to cork the bottle until effervescence has entirely ceased. 5. This prescription was filled by dissolving the quinine sul- phate in the acid and mixing with the mucilage, and then adding the oil of cloves. The potassium permanganate was dissolved in a little water and added slowly to the other mixture. Dark-brown masses were formed, consisting of coagulated acacia holding in it the manganese dioxide, the permanganate being reduced. It was almost impossible to mix these masses so as to make a homogeneous mixture or 158 INCOMPATIBILITIES IN PRESCRIPTIONS. even one that would pour readily. On standing a few hours the manganese dioxide is further reduced to manganous sul- phate and the mixture becomes colorless. The patient using this prescription had it refilled several times. 6. The alcohol of the tincture throws the acacia out of solu- tion and the water of the mucilage precipitates the resin from the tincture so that a white precipitate ultimately forms in the bottom of the bottle. A fresh tincture of guaiac with mucilage of acacia gives a blue color but an old tincture gives a brown-red color. With the consent of the physician the prescription was filled by using glycerin and water instead of mucilage. 7. The sodium hypophosphite is deliquescent in damp air and the powders become moist. Chemical reaction then takes place, causing the mixture to become yellow and finally black. The hypophosphite reduces the bismuth to a yellow and then a black compound, in which the quantivalence of bismuth is two, while the hypophosphite is oxidized to a phosphate. The dampening of the extract of nux vomica also tends to darken the mixture. By adding some althea and using oiled or parchment paper the mixture can be dis- pensed without difficulty. The directions translated into English are: Mix, make a powder, and divide it into 25 equal parts. 8. The mercuric chloride combines with the sodium and ammonium iodides, forming insoluble mercuric iodide, which redissolves in excess of the alkali iodides, forming a double compound that precipitates some of the constituents of the compound syrup of sarsaparilla. Ammonium iodide very INCOMPATIBILITIES IN PRESCRIPTIONS. 159 frequently contains a little free iodine, which probably com- bines with some of the organic matter present in the syrup. There is no danger of the potassium chlorate liberating iodine from the iodides so long as the mixture is neutral or alkaline. Corrosive sublimate is slowly reduced to calomel by the com- pound syrup of sarsaparilla (U. S. D., 689). 9. If the first tw^o ingredients are triturated together an explosion is liable to occur. If, however, they be dissolved separately in the water and then mixed there is probably no danger. If the solution were acid chemical reaction w^ould take place with the formation of hydrochloric and phosphoric acids. 10. When these two substances are rubbed together in a mortar with considerable force a damp powder or a soft mass is formed which soon dries. By powdering the ingredients, separately and then mixing no difficulty is experienced. The mixture does not make a clear solution in water, an aluminum salt being precipitated. 11. This mixture is quite frequently prescribed by physicians, even by those who know that it is incompatible. A chemical reaction takes place between the nitrous ether and the tannin in the buchu, causing an evolution of oxides of nitrogen. Spirit of nitrous ether sometimes reacts with an aqueous solu- tion of potassium acetate, giving ofif a gas, the composition of which has not been definitely determined. The gas must be allowed to escape before corking the bottle. Some of the resinous matter in the fluid extract will be precipitated by the water. l6o INCOMPATIBILITIES IN PRESCRIPTIONS. 12. The tannin in the tincture of digitaHs makes a black inky- mixture with the tincture of iron. The phosphoric acid •added to the tincture of iron before the two tinctures are mixed partially prevents, or if added after partially destroys, the inky color, the final mixture being dark brown and turbid. If two drams of dilute phosphoric acid be added to the tinc- ture chloride of iron the mixture becomes entirely colorless, due to the formation of ferric phosphate, and on the subse- quent addition of a tannin solution the black color is not produced. A little light-colored precipitate is formed. 13. The quinine sulphate and the lead acetate react, forming quinine acetate and lead sulphate, both of which are practi- cally insoluble in the syrup. The bismuth subnitrate is also insoluble. In filling this prescription it is best to add about twenty grains of powdered tragacanth to aid in suspending the insoluble substances. A " Shake well " label should be put on the bottle. 14. Alum, being a soluble sulphate, will react with the lead acetate, precipitating the insoluble lead sulphate according to the following equation: 4Pb(C2H302)2 + K2Al2(SO,),24H20 = 4PbSO, + 2KC2H3O2 + Al2(C2H302)6 + 24H2O. The precipitate should not be filtered out. 15. The tannic acid combines with the quinine, forming the nearly insoluble quinine tannate. This prescription should be filled by dissolving the quinine sulphate in a part of the INCOMPATIBILITIES IN PRESCRIPTIONS. i6i syrup with the aid of the sulphuric acid. The tannic acid should be dissolved in the remainder of the syrup and this o-radually added to the other solution with constant stirring. Both solutions should be cold, because if mixed when warm the precipitate formed is sticky and will make a mass that cannot be evenly divided. 16. Emulsify the cod-liver oil by adding it in portions to the lime water in a bottle. Then add the oil of wintergreen, the syrup, and the syrup iodide of iron. The calcium hydrate of the lime water saponifies a small amount of the cod-liver oil, which soap helps to emulsify the balance of the oil. When the syrup of ferrous iodide is added to the mixture containing the calcium hydrate ferrous hydrate is precipitated. Ferrous hydrate if free from ferric hydrate is white, but it quickly oxidizes to ferroso-ferric hydrate, which varies from a dirty green to almost black. After some time it is oxidized to a yellow-brown basic ferric oxide. This prescription will go through these various colors. 17. Donovan's solution precipitates many alkaloids from aqueous solutions of their salts. Quinine is no exception. This prescription was filled by dissolving the quinine sulphate in most of the syrup with the aid of the acid; dissolving the potassium iodide in the remaining syrup and adding to the first solution. Donovan's solution was then slowly added with constant stirring and the prescription sent out with a " Shake well " label. The danger in such a prescription does not come from the quinine which is precipitated, but the mercuric salt which is precipitated with the quinine. In concentrated solutions of quinine potassium iodide gives a precipitate. At the end of two days all of the mercury was precipitated and some iodine was liberated, the sulphuric acid displacing the hydriodic acid and the air oxidizing the hy- l62 INCOMPATIBILITIES IN PRESCRIPTIONS. driodic acid. Any quinine not precipitated by the Donovan's solution was precipitated by the iodine. 18. There is not a sufficient amount of water to dissolve all of the quinine sulphate. If the sodium salicylate is dissolved in part of the syrup and the quinine is mixed with the balance of the syrup and these two brought together a bulky gelatinous precipitate of quinine salicylate is formed. The resulting mixture is so thick that it can be poured only with difficulty. When a little sulphuric acid is used to aid the solution of the quinine sulphate, the precipitate of quinine salicylate subsequently formed is generally more bulky and tenacious. 19. The mercuric chloride precipitates the strychnine sulphate as a double compound, which is soluble in a fairly strong alcohol, less soluble in the presence of hydrochloric acid. This prescription deposits a precipitate of long needle-shaped crystals on standing a few hours, but not immediately on filling. If the first ingredient is omitted no precipitation takes place within at least twenty-four hours, although there is danger of precipitation after the patient has received it. The addition of a few drops of hydrochloric acid quickly brings it down. This prescription as written should not be filled. If the mercuric chloride be omitted there will be but little danger of precipitation. 20. If the first two ingredients are dissolved in separate por- tions of the elixir and then mixed a clear solution results. This, however, becomes turbid in a few minutes, and the liquid separates into two layers, the upper one having some- what of an oily appearance. This oily liquid is chloral alco- INCOMPATIBILITIES IN PRESCRIPTIONS. 163, holate, formed from the chloral hydrate and the alcohol of the elixir. Just what part the potassium bromide takes in the reaction seems not to be well understood, unless it be to render the alcoholate less soluble in the elixir. Other inorganic salts, such as sodium bromide or sodium chloride^ act in a similar way. If there is not more than about ten grains of chloral h)'drate and ten grains of potassium bromide in a dram of the solution there is but little danger of the chloral alcoholate separating. Chloral alcoholate is more soluble in alcohol than it is in water, and by the addition of a little more alcohol the separation of the two fluids can sometimes be prevented. This prescription when filled as written may be considered a dangerous one. Several cases have been reported where alarming symptoms have be6n caused by the taking of a teaspoonful of chloral alcoholate. On filling a similar combination, if a turbidity results the mixture should be kept until it can be determined whether there will be a separation into two layers, and if so, then remedied by adding a little alcohol or putting on a " Shake well " label. 21. A reaction takes place between the first two ingredients, with the precipitation of lead sulphate. All of the lead is precipitated. If the lead subacetate is dissolved in water and then added to the tinctures it will precipitate the alkaloids of the opium as well as other matter. Water also causes a precipitation of the resinous matter from the tinctures. This prescription should be dispensed without filtering, but with a " Shake well " label. 22. Mercuric chloride combines with albumin to form a com- pound insoluble in water. The presence of an equal weight or more of sodium or ammonium chloride prevents to a con- siderable extent the formation of the precipitate. " By l64 INCOMPATIBILITIES IN PRESCRIPTIONS. dissolving one part of corrosive sublimate and a hundred parts of common salt in distilled water and evaporating to dryness a soluble double preparation is obtained w^hich does not coagulate albumen." (U. S. Dispens., 689.) If this prescription were filled as directed it would be practically inert. By adding three or four grains of ammonium chloride to the mercuric chloride, dissolving this in about one half the water and the albumin in the remainder of the water, and mixing these solutions, a nearly clear solution can be ob- tained. 23. Sodium phosphate requires 5.8 parts of water to dissolve it; consequently in this prescription it would not be all dis- solved. It should be powdered before adding to the syrup and water and the prescription then dispensed with a " Shake well " label. 24. The syrup of garlic contains acetic acid, which combines with the ammonium of the ammonium carbonate, liberating carbon dioxide. The reaction should be completed before the bottle containing the solution is corked, or the pressure of the gas formed may be sufficient to burst the bottle. 25. The zinc is entirely precipitated by the borax, producing a white flocculent precipitate of zinc borate or a mixture of the borate with a basic compound. The prescriber should be advised of this fact. If the prescription is dispensed the pre- cipitate should be filtered out. 26. The spirit of nitrous ether is generally acid in reaction, and when an acid solution of nitrous ether is brought in con- INCOMPATIBILITIES IN PRESCRIPTIONS. 165 tact with potassium iodide, iodine is liberated and the gas nitric oxide is formed. This prescription should not be filled on account of the free iodine formed. 27. Several chemical reactions occur, depending on the order of mixing the ingredients. The possible reactions are as follows: I. The potassium iodide in the compound tincture of iodine when mixed with a solution of ferric chloride forms free iodine, potassium chloride, and ferrous chloride. 2. Fowler's solution is alkaline, due to the presence of potassium bicarbonate and perhaps some normal potassium carbonate. This carbonate neutralizes part of the free hydrochloric acid when mixed with the tincture of iron, forming potassium chloride and carbon dioxide. 3. Ferric chloride with phos- phoric acid forms the colorless ferric phosphate, which is insoluble in water, but soluble in water containing free acid. 4. Tincture chloride of iron dissolves quinine sulphate, the free acid of the tincture combining with the quinine sulphate to form a more soluble compound. 5. The iron combines with tannic acid in the rhubarb, forming the black tannate of iron. 6. The free iodine in the compound tincture of iodine combines with sulphate of quinine, forming an insoluble •compound. 7. The free iodine will also combine with the tannin in the rhubarb. 8. The alkali in Fowler's solution will neutralize part of the phosphoric acid when mixed with it. 9. The alkali in Fowler's solution when mixed with a solution of quinine sulphate combines with the sulphuric acid, liberating and precipitating the free alkaloid. 10. The phosphoric acid is a solvent for quinine sulphate, probably combining with it and under certain circumstances again precipitating it. 11. A solution of quinine sulphate is pre- cipitated by the tannic acid of the rhubarb, forming the in- soluble tannate of quinine. In w^hatever way the ingredients are mixed the combina- tion is an extremely inelegant one; it is black and inky in 1 66 INCOMPATIBILITIES IN PRESCRIPTIONS. color and taste, and the quinine and rhubarb are not in solu- tion. 28. Pure ferric pyrophosphate of iron is insoluble in water. The ofiEicial soluble pyrophosphate of iron may be a double compound of sodio-ferric citro-pyrophosphate, or it may be a mixture of ferric pyrophosphate and sodium citrate, the former being soluble in a solution of the latter. When sul- phuric acid is added to the solution of this compound or mix- ture the ferric pyrophosphate is precipitated, the sulphuric acid probably combining with the sodium and liberating citric acid. The quinine is not precipitated. 29. This makes a clear brownish-red solution, which on stand- ing two or three days loses much of its color. The color varies with the proportion of free iodine which also varies with the condition of the soap liniment. Soap, oil of rosemary,, and camphor all reduce the iodine to some extent. In some cases all of the iodine is changed so that it no longer gives a test with starch. The products formed are not well known. 30. An old specimen of bismuth and ammonium citrate is generally not entirely soluble in water unless a little ammonia water is added. At best the solution of this salt is usually slightly alkaline, and the pepsin on being added to this is rendered inert by the alkali. If, however, the hydrochloric acid is used in dissolving the pepsin in w-ater and this solution added to the bismuth and ammonium citrate dissolved in the balance of the water, the action of the pepsin will not be destroyed, but a precipitation will take place. This precipi- tate is bismuth citrate, the hydrochloric acid breaking up the double salt and combining with the ammonia. Pepsin should INCOMPATIBILITIES IN PRESCRIPTIONS. 167 not be prescribed with bismuth and ammonium citrate, as one or the other loses much of its activity. When such a pre- scription is to be filled it is best to dissolve each ingredient separately, making each solution neutral before mixing them. 31. When the sulphurous acid is added to the solution of the sodium hypophosphite in the cinnamon water a turbidity re- sults, due to the separation of free sulphur. The hypo- phosphite is oxidized to a phosphate and the sulphurous acid is reduced to sulphur. In the presence of a very large excess of the hypophosphite the sulphur is further reduced to hy- drogen sulphide. 32. Potassium iodide is hygroscopic in a moist atmosphere and powders containing it usually become damp. There is no reaction between calomel and potassium iodide if the mixture is dry, but mixed in the above proportions in the presence ■of moisture a dark-gray powder is produced. Mixed in more nearly equal proportions a yellowish-green powder is formed. Chemical reaction takes place, with the formation of potas- sium chloride and mercurous iodide, which is yellow. The mercurous iodide is decomposed by the excess of potassium iodide, forming a double salt of potassium and mercuric iodide and metallic mercury, and it is the metallic mercury that gives the mixture the gray color. This prescription should not be dispensed, because of the oxidation of the mercurous compound to the much more active mercuric com- pound, or if it is, the dose should be reduced to correspond with that of the mercuric salt. The directions are: Mix, make a powder, and divide into 10 powders (papers). 33. If the acid is added to the tincture a red coloration is formed at contact of the two liquids. This red color quickly l68 INCOMPATIBILITIES IN PRESCRIPTIONS. changes to an orange and then to a yellow when the liquids are mixed. The changes in color are probably due to the action of the acid on the brucine. If now the mixture is allowed to stand a short time a chemical reaction is evidenced by the evolution of bubbles of gas. This reaction continues slowly for several hours, and is due to the acid acting on the organic matter other than the alkaloids, probably tannin. The dilution with the elixir does not prevent it. On adding the acid or the elixir to the tincture a precipitate of inert matter is produced. 34. There is not enough of water to dissolve all of the quinine sulphate, as it requires 740 parts of water. The water will precipitate inert extractive matter from the tincture. While potassium iodide does not always precipitate strychnine sul- phate when in solution with it, there is some danger of precip- itation. (See the incompatibilities of strychnine.) The usual maximum medicinal dose of strychnine sulphate is V12 oi a. grain. In this prescription the dose is ^/^q of a grain and is dangerously large. The prescription should not be dispensed without first having called the prescriber's attention to that fact, as well as to the possibility of the strychnine being pre- cipitated by the potassium iodide. 35. The wine of pepsin of the National Formulary contains hydrochloric acid and the syrup of ipecac contains acetic acid. There is a suf^cient amount of ammonium carbonate to neutralize both of these acids and render the solution alka- line, thereby destroying the activity of the pepsin. In the reaction carbon dioxide is given ofif and the bottle must not be corked until the reaction is complete, for the pressure o£ the gas might burst the bottle. INCOMPATIBILITIES IN PRESCRIPTIONS. 169 36. If the directions to rub these solids together be followed an explosion will probably result. Potassium chlorate forms an explosive mixture with each of the three other ingredients. Each substance should be powdered separately and all mixed together lightly. Some pharmacists would decline to fill this prescription. If filled, however, the patient should be in- formed of the nature of the mixture and cautioned to keep it where there will be no danger of its receiving a blow be- tween two hard surfaces. 37. If these ingredients are mixed together and allowed to stand the oil of turpentine will rise to the top. The oil should first be emulsified with the syrup and about forty-five grains of acacia and then the other liquids added. When water is added to paregoric the oil of anise and the benzoic acid are precipitated, but these would be held in suspension by the emulsion. Sometimes the solution of ammonium acetate is alkahne, there having been an excess of ammonium carbonate or a deficient amount of acetic acid used in making it. In such a case the acid in the syrup of squills will liberate carbon dioxide. 38. Evidently the prescriber wished to air a little of his knowledge or then had some kind of an agreement with a certain pharmacist to fill his prescriptions. It is unusual to employ the chemical symbols in writing prescriptions, and it can hardly be expected that the dispenser will know and remember such complicated formulas as the first one and of a compound which is used comparativelyseldom. CigHoiNOg is codeine, KI is potassium iodide, CgHgOg is glycerin, and H2O is water. This prescription was filled by dissolving the codeine in; 170 INCOMPATIBILITIES IN PRESCRIPTIONS. the glycerin and part of the water. The iodide was dis- solved in the remainder of the water and the two solutions mixed, without any precipitation occurring at once. After several days, however, there was a deposit of very fine crystals. Potassium iodide precipitates quite a number of the alkaloids from their solutions. This precipitation can be prevented by having a small amount of alcohol present. 39. The potassium chlorate is soluble in about i6 parts of water; consequently only a small proportion is dissolved in the three ounces of water. Some pharmacists would con- tend that the excess of the chlorate in a powdered condition should be left in the bottle, so that the patient could add water to it as the liquid was used up. This might be all right if it were a simple mixture of the chlorate and water. But in the above prescription, since the fluids are all more or less medicinal, it is evident that the physician wanted only a saturated solution of the chlorate and the excess removed. The resinous matter of the tincture is precipitated by the water. The fluid hydrastis colorless is a preparation which seems to vary much in composition. The U. S. Dispensa- tory gives a method of making it which consists in dissolving twenty grains of hydrastine sulphate in one pint of a mixture of equal parts of glycerin and water. 40. The copaiba when mixed with the tinctures does not make a clear solution, as it requires from three to four times its amount of alcohol, although it is readily soluble in absolute alcohol. On the further addition of glycerin the mixture was made more turbid and the syrup when added threw out of solution most of the copaiba, which had been dissolved by the alcohol of the tinctures. On standing the copaiba rises to the top, but the syrup and glycerin are viscid enough to INCOMPATIBILITIES IN PRESCRIPTIONS. 171 liold it in suspension for some little time, so that the patient can get a uniform dose. Or this can be made into an emul- sion with the aid of some acacia. It should be dispensed with a " Shake well " label. 41. When the first two ingredients are rubbed together the liquid chloral camphor is formed. This will not dissolve all of the cocaine hydrochloride for which the prescription calls. 5 Dg. is 5 dekagrams or 50 grams, which is undoubtedly a mistake. The prescriber probably meant 5 dg., which is 5 decigrams or one half of a gram. That being the case, the ■cocaine can be readily mixed with the oily liquid. 42. Strong nitric acid decomposes creosote, with the forma- tion of red fumes. Dilute nitric acid converts it into a brown resin. (U. S. Dispensatory, 17th ed., 450.) In filling this prescription the nitric acid should be slowly added to the creosote with constant stirring. A considerable heat is gen • €rated by the reaction, and the mixture should be allowed tC' cool before adding the chloroform, so that it will not be volatilized. It is doubtful if this prescription has much caustic ■effect. 43. Chloral hydrate is decomposed by alkalies, forming chloroform and a formate of the base. Borax is sullficiently alkaline so that chloroform will be slowly generated and can be recognized by the odor. 44. There is considerable danger of having an explosion in attempting to fill this. If the potassium chlorate is rubbed with the glycerin explosion is liable to take place. Or if 1/2 INCOMPATIBILITIES IN PRESCRIPTIONS. the chlorate be added to the solution of ferric chloride, which always contains some free hydrochloric acid, chlorine will be formed, and this will act upon the glycerin, converting it into oxalic and carbonic acids. In filling this the temperature should not go above 70° F., and then the bottle should be loosely stoppered for a time before giving to the patient. The chlorate is not entirely dissolved. 45. The amount of chlorine formed will depend upon the order of mixing the ingredients. If the potassium chlorate and hydrochloric acid are mixed and then the water added a yellow liquid containing much free chlorine with oxides of chlorine will result. If, however, the salt is first dissolved in water and then hydrochloric acid added the amount of chlorine formed will be small. The physician has not indi- cated which was wanted, but probably the latter, as the former would be exceedingly irritating. 46. The usual maximum dose of the tincture of lobelia is sixty minims. This prescription calls for twice that amount. The doses of the other two tinctures are rather large, although not above the maximum. Taking into consideration the fact that the mixture is to be taken every hour, it may be con- sidered a dangerous one and the prescriber should be con- sulted. Another evidence of a mistake having been made is seen in the fact that a three-ounce mixture is obtained with- out using any of the compound syrup of squills at all. Per- haps the physician intended to have omitted the " q. s. ad," thus making a six-ounce mixture. 47. No change is noticed in the appearance of this mixture on standing unless exposed to sunlight when it becomes a dirty INCOMPATIBILITIES IN PRESCRIPTIONS. ^7Z gray. The odor is still prominent at the end of a month. According to the U. S. D. the odor of the iodoform slowly diminishes, due to the decomposition caused by the tannic acid. 48. On triturating these two substances together the mixture becomes black. Ammonium carbonate acts like ammonium hydrate, forming the black compound nitrogen dihydrogen dimercurous chloride (NHaHgaCl). There seem to have been no physiological experiments made with this compound, but, as acids decompose it, probably the gastric juice breaks it up into calomel and ammonium chloride. The ammonium carbonate probably increases the action of the calomel, and may possibly tend to the formation of some mercuric salt. 49. The dose of potassium cyanide is dangerously large, the usual maximum dose being about one fourth of a grain. The physician, knowing that morphine acetate frequently is not entirely soluble, has directed the use of acetic acid. The excess of acid combines with the potassium, liberating hydro- cyanic acid. The potassium cyanide frequently contains a carbonate as an impurity, and in such case might neutralize the free acid and precipitate some of the free morphine. In neutral solutions the potassium cyanide precipitates morphine cyanide from morphine salts. Morphine cyanide is soluble in acid solutions. The prescription should .not be filled. 50. The alcohol in the spirit and tincture as well as the ferric chloride gelatinizes the mucilage of acacia. The gelatinous mass will slowly dissolve in the syrup on standing. The best way to fill the prescription is to dilute the tincture with part: 174 INCOMPATIBILITIES IN PRESCRIPTIONS. of the syrup and mix the rest of the syrup with the spirit and then these with the mucilage. In this way the gelati- nization is avoided. 51. Several chemical reactions are possible in filling this pre- scription, depending upon the order of mixing the ingredi- ents. If the potassium bicarbonate is added to the syrup of lemon carbon dioxide will be liberated by the citric acid. Spirit of nitrous ether is usually acid with nitrous and nitric acids, and these will liberate the carbon dioxide if brought in contact with the bicarbonate. The solution of potassium hydrate is capable of neutralizing the acid in the spirit or part of that in the syrup. The spirit of nitrous ether if added directly to the fluid extract will cause a reaction, with the evolution of red fumes. This will not take place as readily if the solution of potash is added to the spirit first. Some of the resinous matter in the fluid extract is precipitated by the syrup. The gas which is formed should be allowed to escape before corking the bottle; otherwise an " explosion " might result. 52. This prescription resembles Blaud's pills, inasmuch as the potassium carbonate reacts with ferrous sulphate in the pres- ence of moisture to form the green ferrous carbonate. This ferrous carbonate oxidizes in the air, forming ferric oxide, and to prevent this some sugar should be added. The potassium carbonate with mercuric chloride gives the red-brown oxy- chloride of mercury, and with strychnine sulphate it gives the free alkaloid. As the mixture is to be made into pills, and the compounds formed are not more active than those pre- scribed, there need be no hesitation about filling the prescrip- tion. It may be filled by following the general directions in the U. S. P. for making Blaud's pills. The mass is strongly alkaline. INCOMPATIBILITIES IN PRESCRIPTIONS. 175 53. If these three ingredients are mixed in the absence of moisture no change in appearance is noticeable. In the presence of moisture the mixture at once begins to turn gray. This is due to the formation of metallic mercury and mercur- ous oxide, while at the same time some mercuric chloride is formed (M. M. R., vii. 492). The sodium bicarbonate seems to play some part in the reaction since calomel and antipyrin with water do not readily darken. This should be considered a rather dangerous prescription. 54. On standing the citric acid in the syrup combines with the sodium, liberating salicylic acid, which, being only spar- ingly soluble in water, is precipitated in needle-shaped crystals. This can be dispensed as a shake mixture. The precipitation is rather tardy, and it would be well to inform the patient of the change which will take place. 55. Reaction takes place between the potassium iodide and the ferric chloride, forming free iodine, ferrous chloride, and potassium chloride. Potassium iodide and spirit of nitrous ether react, forming free iodine and nitric oxide. Gentian is said to contain no tannin, but the other drugs with which it is combined in the compound tincture do. The tannin com- bines with the iron to form the black inky ferric tannate. This prescription should not be dispensed on account of the free iodine formed. The iodine is not precipitated. 56. If the solution of dialyzed iron has been improperly made and is strongly acid no precipitation occurs. But if it is nearly neutral, as it should be, ferric hydrate is precipitated 176 INCOMPATIBILITIES IN PRESCRIPTIONS. by the alkali that is in Fowler's solution. The ferric hydrate forms with the arsenic an insoluble compound of basic ferric arsenite, which to some extent changes to ferrous arsenate. Though liquid at first the mixture may gelatinize after several days. 57. Giving but a glance at this prescription we would con- clude that it should not be dispensed, that the strychnine would be precipitated. But upon closer study we find that the solution of strychnine, B. P., is an acid hydro-alcoholic solution containing about one per cent, of strychnine hydro- chloride. On adding sodium bicarbonate to this the hydro- chloric acid combines with it, and the strychnine is liberated, but not precipitated. Strychnine (free alkaloid) is soluble in about 6700 parts of water. In this prescription we have only about .015 Gm. in 100 Cc. or i part to 7500 of water, a sufficient amount of water to keep the alkaloid in solution. 58. In making Fowler's solution the excess of potassium bi- carbonate used is changed to the carbonate by boiling and the carbonate makes the solution alkaline. Potassium carbonate precipitates a solution of mercuric chloride as the basic mer- curic chloride. In this prescription there may be a red-brown precipitate of the oxychloride of mercury but more generally a white precipitate of calomel forms. An arsenite in an alkaline solution reduces mercuric chloride to mercurous chloride and in excess to metallic mercury. Had the pre- scriber used the solution of arsenous acid instead of potassium arsenite no trouble would have resulted. The compounder should neutralize the Fowler's solution with hydrochloric acid before adding to the solution of mercuric chloride. 59. On dissolving the quinine sulphate in part of the cinnamon water with the aid of the sulphuric acid, then adding the INCOMPATIBILITIES IN PRESCRIPTIONS. 177 potassium acetate previously dissolved in the remainder of the water, a voluminous precipitate of quinine acetate is ob- tained. Quinine acetate is only sparingly soluble in v^ater, and the amount here formed is so large and bulky that it is difificult to pour out an even dose. 60. Different results are obtained, according to the order of mixing the ingredients. If the Fowler's solution is added to the solution of dialyzed iron ferric hydrate is precipitated, and this combines with the arsenic to form an insoluble basic ferric arsenite. But if the syrup is added to the iron and the Fowler's solution is diluted a little with water and then added to the iron, little or no precipitation takes place. Sugar to some extent acts as a solvent for the ferric hydrate. Solu- tion of dialyzed iron varies considerably in the amount of acidity which it has; if properly made it is nearly neutral. Some samples are sufficiently acid to prevent any precipita- tion by Fowler's solution. There is some danger of the strychnine being precipitated by the alkali in the Fowler's solution. Syrup or water added to the tincture of cinchona causes a turbidity. The tannin in the tincture will make a black mixture with the iron. To avoid the precipitations noted above the solution of potassium arsenite should first be neutralized with hydrochloric acid ; or a better way would be to get the prescriber to use the solution of arsenous acid instead of potassium arsenite. The directions translated into English are: Mix. Label: Let a teaspoonful be taken after dinner. 61. The dose of aconitine is entirely too large unless the par- ticular sample to be used has been proved to be compara- tively inert. Two and one half grains of a so-called aconitine have been taken without ill effects, while ^/i28 of a grain has been reported to have caused death. The commencing 178 INCOMPATIBILITIES IN PRESCRIPTIONS. dose of absolute aconitine should not be much over Veoo of a grain. In this prescription there are several physiological incompatibilities. In action aconitine is more or less opposed to morphine, strychnine, and belladonna. Morphine is to some extent antagonistic to atropine and strychnine, and atropine to strychnine. 62. This makes a clear colorless solution at first. In a day or two it acquires a yellow color which deepens. The prod- ucts formed have not been determined. A similar prescrip- tion containing glycerin is sometimes written, and it does, not change in color so readily. 63. The mercuric chloride and ferrous iodide react to form mercuric iodide and ferrous chloride. The insoluble red iodide of mercury thus formed is redissolved in the excess of ferrous iodide. The creosote requires 150 parts of water for solution. In this case there is an excess of creosote, and it forms an oily layer on top unless it is emulsified. Occasion- ally the solution of ammonium acetate is alkaline, and in such a case it might give a precipitate with the mercuric chloride, forming ammoniated mercury, and with the ferrous iodide, forming ferrous carbonate. 64. The ingredients of this prescription can be mixed so as to make a homogeneous mass, but on standing for a few days the balsam separates from the petrolatum. This can be pre- vented by incorporating one and a half drams of simple cerate or of lanolin in place of a like amount of petrolatum. The odor of iodoform is gradually lost, due, according to the U. S. P., 741, to the formation of a new compound. INCOMPATIBILITIES IN PRESCRIPTIONS. 179 65. This gives a clear solution at first but after a day or two a precipitate is formed. The precipitate gives a test for both arsenic and iodine. There may be an oxy-iodide of arsenic formed. If this mixture is dispensed at all it should be with, a " Shake well " label. 66. The euphorin, aristol, tannic acid, and alum can be triturated together, producing a powder. On adding the crystallized carbolic acid to this mixture, it becomes very soft, almost liquid. This change is the result of bringing carbolic acid in contact with the euphorin, these two sub- stances liquefying when triturated together. The mass with the oil of theobroma makes a mixture too soft to be made into suppositories. It is necessary to render it firmer by the addition of wax, spermaceti, or some absorbing powder, as, starch or slippery elm. 67. Although the sulphuric acid aids the solution of the quinine sulphate, it precipitates the glycyrrhizin of the fluid extract. The glycyrrhizin, thus precipitated as glycyrrhizic acid, loses much of its sweet taste and no longer disguises the taste of the quinine. It would have been better if the prescriber had omitted the sulphuric acid and directed a shake mixture. The water causes the separation of a small amount of inert matter from the fluid extract, 68. Several chemical reactions take place, depending upon the manner of filling this prescription: i. Between the hydro- chloric acid in the tincture and the potassium chlorate, liberat- ing chlorine. 2. The chlorine thus formed may act upon l8o INCOMPATIBILITIES IN PRESCRIPTIONS. the glycerin or alcohol. 3. Between the hydrochloric acid and the ammonia and glycyrrhizin in the fluid extract, pre- cipitating the glycyrrhizic acid. 4. Between the iron and tannic acid in the fluid extract, giving the black tannate of iron. 69. The dose of the arsenic and of the strychnine is between V7 and Vs of ^ grain in this prescription. The* maximum dose of each, as generally given, is not over Vio o^ ^ grain. The prescriber should be consulted. Moreover, each pill would contain about seven grains of medicinal matter, which, considering the bulky quinine sulphate and extract of gentian, makes a very large pill. Where such a large pill is prescribed, twice as many pills are sometimes made as directed and then the number to be taken at one time is doubled. 70. Water can be added to carboHc acid, until the proportion is about 3 parts of acid to i part of water, forming a clear solution (Allen, Organic Analysis, 11, 537). On adding more water the acid separates as an oily liquid, going to the bottom. When water has been added so that the pro- portion is about I part of acid to»i5 parts of water, a clear solution again results. In this prescription there will be a layer of liquefied acid in the bottom of the bottle. If the brush should remain in the bottle between the periods of using it there is danger that it will become saturated with the strong acid and that the patient will apply it in this condi- tion. By the use of two drams of glycerin in place of part of the water a clear solution can be made, and this is what the dispenser should use. 71. If the tincture of iron is added directly to the mucilage of acacia the acacia is gelatinized by the iron. This gelatinous INCOMPATIBILITIES IN PRESCRIPTIONS. i8l mass will redissolve after standing for some time with the other ingredients, but can be avoided by diluting the iron ^vith the other ingredients first. When an acetate or acetic acid is added to a solution of a ferric salt the solution turns a deep red, due to the formation of ferric acetate. 72. Different results may be obtained by changing the order of mixing these ingredients. If the corrosive sublimate is dissolved in the water and then added to the lime water the yellow mercuric oxide is precipitated. This if mixed with the mucilage and allowed to stand for some time changes to a dirty-brown color. If the lime water is added to the solu- tion of mercury the red-brown basic chloride of mercury is precipitated. If the solution of mercuric chloride is added to the mucilage of acacia and then the lime water added to this no precipitation of mercury takes place. On allowing this to stand for a few days a flocculent precipitate is formed, slowly increasing. Acacia prevents the precipitation of a number of the heavy metals by the alkaline hydrates. 73. The bismuth subnitrate is insoluble in the syrup, but a chemical reaction takes place between it and the hydriodic acid, as is evidenced by the change in color. Bismuth sub- nitrate is white; on mixing it with the syrup the color be- comes yellow, and within a few minutes it turns to a dark brown and then grayish black. On allowing the precipitate to settle it appears to be a mixture of two compounds, one yellow and the other dark gray. According to Watts' Dic- tionary, the oxyiodide of bismuth is copper-colored and the bismuth iodide is a brilliant gray. 74. Some samples of pepsin are hygroscopic and in such a case the powders may become damp. Pepsin is rendered l82 INCOMPATIBILITIES IN PRESCRIPTIONS. inert by alkalies, as sodium bicarbonate. The prescriber said that he gave the soda where the bowels are locked to some extent, so as to neutralize the acid and allow freer movements. 75. The sodium phosphate of the U. S. P. is the Na2HP04 and is slightly alkaline to litmus. This alkalinity may cause precipitation of the strychnine, and it should be neutralized with a little phosphoric acid before the solutions of sodium phosphate and strychnine sulphate are mixed. 76. If the turpentine is poured upon the iodine violent chemical reaction results, with the formation of violet fumes of vaporized iodine, caused by the heat generated. While there is not enough of alcohol to dissolve all of the iodine, it is best to dissolve as much as possible before adding the turpentine, which should be added in small portions, cooling the mixture if necessary. Upon standing the liquid separates into two layers. The lower one, being much smaller in amount and very dark colored, is probably the alcohol hold- ing most of the iodine in solution ; the upper stratum is very much lighter in color and is probably the turpentine. Tur- pentine and alcohol are not miscible in all proportions. 77. According to the National Formulary, Hall's solution of strychnine contains Vs of ^ grain of strychnine acetate to the dram, together with some acetic acid. Fowler's solution contains, besides the potassium arsenite, some potassium bi- carbonate or carbonate (formed by the boiling of the bicar- bonate in water). This carbonate will react with the acetic- acid, liberating a little carbon dioxide and forming potassium- acetate. If there is an excess of the alkaline carbonate the strychnine will be liberated as the free alkaloid.. The INCOMPATIBILITIES IN PRESCRIPTIONS. 183 Strychnine will not be precipitated, however, as it is soluble in no parts of alcohol, and the prescription can be filled without difficulty. 78. The resinous matter in the tincture of myrrh is precipi- tated by the syrup. By adding the tincture to the syrup in small portions and shaking well after each addition the resin comes down in .a form in which it can be more readily sus- pended in the liquid. Tannic acid combines with the mor- phine to form a compound insoluble in water. It is difficult if not impossible to get an even dose of morphine. 79. In filling this prescription each of the salts was dissolved in separate portions of water. The potassium iodide solution was added to the mercuric chloride solution, and at first there was a,red precipitate of mercuric iodide, which was dissolved by the further addition of the potassium iodide, forming the soluble potassium mercuric iodide. On the addition of the ammonium carbonate solution to this no change of any kind was noticed. However, when the ammonium carbonate solu- tion was added to the mercuric chloride solution a white pre- cipitate of ammoniated mercury was formed. On adding the potassium iodide solution to this mixture the precipitate dis- appeared and a clear nearly colorless solution was formed. Probably the ammoniated mercury was decomposed and the soluble double compound of potassium mercuric iodide was formed. 80. When the ingredients of this prescription are mixed the liberation of iodine commences at once and continues for some time. The wine and spirit were mixed and neutralized with ammonia, thinking thereby to prevent the formation of l84 INCOMPATIBILITIES IN PRESCRIPTIONS. iodine. However, iodine was set free within an hour and in two hours the Hquid had assumed a dark-brown color. When an excess of ammonia is used a dark-green color is pro- duced, probably due to the formation of a ferroso-ferric com- pound, and the liberation of iodine is prevented for a time. Such addition of ammonia is not admissible. Filled as written the iodine is precipitated in time. The prescription should not be dispensed. 81. This mixture in a short time becomes yellow and within twenty-four hours it changes to a light brown. The colora- tion is due largely to the action of the nitrous acid on the morphine. Less change takes place if the mixture is neutral. The morphine is converted into nitroso-morphine, pseudo- morphine, and another base (M. & M., iii. 436). 82. Potassium chlorate with organic matter makes a mixture which can be quite easily exploded. A store was nearly de- molished and the compounder received serious injuries by an explosion caused by rubbing salicylic acid and potassium chlorate in a new Wedgwood mortar. If the ingredients, are powdered separately and then mixed lightly there is but little danger to the pharmacist. Perhaps the patient should be informed of the nature of the mixture. 83. The pharmacist who received this prescription in attempt- ing to fill it rubbed the three ingredients together dry and caused an explosion, whereby he was quite severely injured. The explosion was due to the reaction between the chlorate and hypophosphite. The pills can be made by powdering the ingredients separately, then mixing lightly with powdered extract of liquorice and massing with water. INCOMPATIBILITIES IN PRESCRIPTIONS. 185 84. Iodine is soluble in about 10 parts of alcohol. As much of the iodine as possible was dissolved in the alcohol and then the camphor dissolved in this. This solution was then gradually added to the mercurial ointment with constant trituration and the water was added last. On standing a few minutes a red precipitate was formed and the mixture sep- arated into three layers. In the bottom was this red pre- cipitate, probably mercuric iodide, then a layer of fatty matter, and on top a hydro-alcoholic fluid containing free iodine. This mixture was such that it could be shaken up and applied. On the third day the red precipitate had disappeared, leav- ing the yellow fatty matter and a fluid somewhat red and containing a little free iodine. Seven days later the liquid was yellowish brown and contained only a trace of iodine. Part of the iodine probably combined with the mercury to form mercuric iodide, and part was probably reduced to a soluble iodide, which dissolved the mercuric iodide. Another part of the iodine probably combined with some of the cam- phor and fatty matter. Although the activity of the iodine is very much diminished the mixture is decidedly active on account of the mercuric salt formed. 85. " Creolin is said to be an emulsion of cresol, obtained by means of resin soap. Creolin forms a milky emulsion or mix- ture with water." (U. S. Dispensatory. 1610.) This prescription may be filled by dissolving the acid in the water and adding the creolin slowly with constant shak- ing. Part of the creoHn separates on standing, but it may be readily mixed by agitation. As this is an eye-lotion and not clear, an attempt was made to filter it, but with the result of separating nearly all of the creolin. It should be dispensed with a " Shake well " label. l86 INCOMPATIBILITIES IN PRESCRIPTIONS. 86. The citric acid should be dissolved in the boiling water and then the magnesium carbonate added to this. Carbon dioxide is liberated and magnesium citrate goes into solution. The addition of borax does not cause any precipitation, al- though the solution is alkaline. If the borax is added to the solution of citric acid and then the magnesium carbonate a large amount of the last ingredient is not dissolved, the acid having been nearly neutralized by the borax. 87. Gold and sodium chloride precipitates the sulphates of atropine and strychnine and the alkaloids in cinchona. There is about thirty per cent, of alcohol present but not enough to prevent precipitation. By dissolving the gold and sodium chloride in water and adding an equal weight of sodium thio- sulphate a compound is formed that does not precipitate the alkaloids from this mixture. The gold may be reduced on standing for some time. Water precipitates inert matter from the fluid extract. Atropine and strychnine are somewhat an- tagonistic in their physiological action. 88. In medium-sized medicinal doses morphine and atropine are physiologically incompatible. But the minute dose of atropine in this prescription assists rather than diminishes the action of morphine by relieving the cardiac depression, indi- gestion, and constipation. 89. The pharmacist should not use the excipient directed. Potassium permanganate is easily reduced by organic matter, which it in turn oxidizes. Some excipient must be chosen that will not reduce the permanganate. A mixture of equal INCOMPATIBILITIES IN PRESCRIPTIONS. 187 parts of petrolatum, paraffin, and kaolin makes a good one, or resin cerate with althea may be used. 90. The oil of turpentine reacts with the acids, with the gen- eration of much heat, and unless care be taken it will be ignited. The acids should be mixed and cooled and then added in small portions to the oil, cooling after each addi- tion. The alcohol should be added last, after the mixture is cold, so as to avoid volatilization. 91. On mixing the acid with the bicarbonate in the presence of water effervescence takes place, due to the liberation of carbon dioxide; a nearly colorless quite strongly alkaline so- lution results. If this is allowed to stand undisturbed for two or three days the lower part of the liquid will be of a light-brown color and the upper part of a dark brown, and finally it will become dark brown throughout. An aqueous solution of a salicylate turns dark when exposed to the air, probably on account of the formation of some oxidation products. This change takes place much more quickly when the solution is alkaline. If the physician had prescribed sodium salicylate instead of the salicylic acid and sodium bicarbonate he would have gotten the same physiological effect, made a better preparation pharmaceutically, and saved the pharmacist considerable time and work. The patient should be informed of the change of color that will take place. 92. This can be filled by dissolving the alkaloidal salts in the syrup of lemon and tincture of iron, adding the water, and then the phosphoric acid last. The solution is clear and of a pale reddish color previous to the addition of the acid. After the addition of the acid the solution becomes colorless and 1 88 INCOMPATIBILITIES IN PRESCRIPTIONS. slightly turbid and in a few minutes a heavy precipitate is- formed. The three disturbing causes are tincture of iron, phosphoric acid, and quinine sulphate, leaving out any one of which prevents precipitation. If the amount of quinine is reduced to three grams there is but little precipitation and none if it is reduced to tw'o grams. The decoloration is due to the formation of ferric phosphate, w^hich is insoluble in water but soluble when there is an excess of free acid. 93. This was filled by dissolving the antikamnia in the elixir with the aid of heat; there was no separation at once. The quinine bisulphate was then added and an effervescence took place. A clear solution resulted, which on standing a short time deposited needle-shaped crystals. The solution is al- kaline to litmus. Antikamnia is said to contain acetanilid, sodium bicarbonate, and caffeine. It is probably this bicar- bonate that causes the effervescence with the bisulphate of quinine and at the same time sets free the alkaloid which is precipitated. Some acetaniHd is also precipitated on stand- ing. 94. The first two ingredients when mixed give a greenish- brown solution, which when diluted with water gives a deep-blue color and largely diluted gives a violet color. On adding the sulphurous acid the color is destroyed within a few minutes. -The ferric chloride is reduced to the ferrous chloride and sulphate, and a ferrous salt does not give a coloration with carbolic acid. If the sulphurous acid is added direct to the tincture of ferric chloride a deep-red solution of ferric sulphite is formed, which changes to ferrous sulphate and becomes colorless. Adding the carbolic acid to this gives no coloration. It makes little or no difference what order is. observed in filling this prescription. INCOMPATIBILITIES IN PRESCRIPTIONS. 189 95. Ferrous sulphate usually contains some ferric sulphate and this reacts with the calcium hypophosphite to form ferric hypophosphite and calcium sulphate, the former being only sparingly soluble, and the latter requiring 380 parts of water for solution. Part of the sulphuric acid of the Epsom salt will go to form calcium sulphate. In an acid solution the potassium chlorate would have an oxidizing efifect on the ferrous sulphate and also on the hypophosphite; in this pre- scription it probably has but little chemical action. The solution of strychnine is a British preparation containing about one per cent, of strychnine hydrochloride. Potassium chlorate and a hypophosphite should not be triturated to- gether dry, as they form an explosive mixture. 96. This mixture makes a clear alkaline solution, colorless at first, but in a few minutes acquiring a light-brown color, which slowly becomes dark red-brown or almost black. This coloration is due partly to the alkaline salicylate acquiring a red color in the air, and partly to the efifect of action of the spirit of nitrous ether upon the salicylate. Prof. Attfield suggests the formation of nitrosalicylic acid which is colored. The change does not take place quite as rapidly when the spirit is mixed with the carbonate previous to the dissolving of the sodium salt. Generally the spirit of nitrous ether is acid, and when ammonium carbonate is added to it carbon dioxide is given ofif. 97. This was filled in several ways, the result being the same. The codeine was triturated with a little water and a half dram of dilute phosphoric acid added to dissolve the alkaloid. The hydrocyanic acid was next added, and then the tincture of iodine, which did not precipitate the alkaloid, but was itself 190 INCOMPATIBILITIES IN PRESCRIPTIONS. decolorized at once. Tlie furtlier addition of the water sim- ply diluted the solution. If the tincture of iodine is added to the solution of codeine in water and phosphoric acid a reddish-brown precipitate is formed, consisting of codeine and iodine. This precipitate is not dissolved by adding an excess of phosphoric acid or sulphuric acid, but the twenty minims of dilute hydrocyanic acid dissolves the precipitate and makes a clear colorless solu- tion. The explanation is that the hydrocyanic acid reduces the iodine to an iodide and thus breaks up the compound of codeine and iodine. Other reducing agents, as sodium hyposulphite, have a similar effec," 98. Reaction takes place between the calcium hydrate and the mercurous chloride, forming calcium chloride and the black mercurous oxide. This is similar to the " black wash " of the National Formulary. 99. The best way to fill this prescription is to dissolve the corrosive sublimate in the glycerin mixed with a half dram of water. Then to this solution add all at once the syrup of lime. A yellow precipitate is formed at first, but this quickly disappears and a clear slightly yellowish liquid results. A slight light-gray precipitate is formed after standing a day, and this increases slowly for several days. Certain or- ganic substances, such as glycerin, sugar, and gum arable, Tiave the power of preventing the precipitation of solutions of some of the metallic salts by alkali hydrates. If the syrup of lime is added slowly to the solution of corrosive sublimate a yellow precipitate is formed, but is re- dissolved again when the water is added. Quite a heavy steel- gray precipitate forms within an hour and it slowly increases on further standing. A similar result takes place if the solu- tion of mercuric chloride is added to the syrup of lime. INCOMPATIBILITIES IN PRESCRIPTIONS. 191 100. Free bromine is formed if the potassium bromide is added to the tincture and the free bromine combines with antipyrin. If the bromide is dissolved in water and then added to the tincture of iron previously diluted with water no bromine is liberated. Antipyrin gives an intense red coloration with the tincture of iron. 101. The compound tincture of iodine was official in the 1870 Pharmacopoeia and contained iodine and potassium iodide dissolved in alcohol. Reaction takes place between the gold chloride and the potassium iodide. " Potassium iodide, added in small portions to a solution of auric chloride (so that the latter is constantly in excess where the two salts are in contact), and when equivalent proportions have been reached^ gives a yellow precipitate of aurous iodide, Aul, insoluble in water, soluble in large excess of the reagent; the precipi- tate is accompanied with separation of free iodine, brown,, which is quickly soluble in small excess of the reagent as a colored solution. But on gradually adding auric chloride to solution of potassic iodide, so that the latter is in excess at the point of chemical change, there is first a dark-green solu- tion of potassio-auric iodide, KIAuIg; then a dark-green precipitate of auric iodide, very instable, decomposed in pure water," forming the yellow aurous iodide. (Prescott and Johnson's Qualitative Chemical Analysis, 4th ed., 154.) Probably the organic matter present also tends to the reduc- tion and precipitation of the gold. The physician should be notified of the change which takes place. Only a very small amount of menthol is dissolved. 102. The usual maximum dose of the fluid extract of digitalis is two minims, some authorities giving it as high as three. 192 INCOMPATIBILITIES IN PRESCRIPTIONS. In this prescription it is about three and a half minims. Taking into consideration the frequency of the dose and that digitalis is cumulative, the pharmacist should decline to fill it until he has consulted the prescriber. 103. No apparent change takes place at first but in less than four hours a yellow-brown precipitate of metallic gold forms. The arsenous acid reduces the gold chloride. It is also easily reduced by many other inorganic compounds as well as by organic matter and light. 104. Tincture of iron if not too strongly acid will give a color varying from a blue to a dirty green with morphine. This color is destroyed by excess of acid or by alcohol. This prescription will give a bluish-green mixture, which will turn to a yellowish orange in a day or two. This latter change is probably due partly to the slow formation of chlorine by the action of the hydrochloric acid in the tincture on the potas- sium chlorate. Chlorine turns a morphine solution orange color. There is not enough water to dissolve all of the chlorate. 105. This gave a clear solution at first but needle-shaped crys- tals began to form within a half hour and by the end of an hour there was quite a heavy precipitate. By the next morn- ing there was so much precipitate that an even dose could not be poured out. Using elixir instead of water does not entirely prevent precipitation and a larger percentage of alcohol is necessary. 106. If the sulphate of iron is strictly ferrous, no liberation of iodine takes place when a solution of potassium iodide is INCOMPATIBILITIES IN PRESCRIPTIONS. 193 added to it, but most of it contains some ferric salt which liberates iodine. If the morphine is now added it will be precipitated by the iodine. The solution of ferrous sulphate gradually deposits a precipitate of subsulphate of iron. Or if the solution of ferrous sulphate and the morphine are mixed before adding the potassium iodide no free iodine is formed, the morphine seeming to reduce the ferric sulphate to ferrous. 107. In massing these two chemicals together reaction takes piace. with the liberation of carbon dioxide, which causes the mass to swell to several times its original size. This reaction .goes on slowly, requiring several hours for completion, and the mass should not be made into pills until the reaction has l^een completed. Had the prescriber directed the subcarbon- ate of bismuth instead of the subnitrate he would have avoided this difficulty and gotten the same physiological effects. 108. If the ingredients are powdered separately and are per- fectly dry when mixed no chemical reaction takes place. The powder will keep for months if protected from moisture. On the addition of water the powder at once becomes dark gray in color. The darkening is due to the formation of metallic mercury; at the same time some mercuric salt is formed, which with the excess of potassium bromide forms a com- pound soluble in water. This is a dangerous prescription and should not be dispensed unless the dose is reduced. If the reaction takes place according to the equation given below, each powder will contain about three tenths of a grain of mercuric salt. Hg^Cl^ + 2KBr = Hg + HgBr^ + 2KCI. 109. Upon bringing together solutions of lead acetate and zinc sulphate, mutual decomposition takes place and lead sulphate 194 INCOMPATIBILITIES IN PRESCRIPTIONS. is precipitated. In a prescription for injection, like this, it is not customary to filter out the precipitate. 110. This mixture gives a nearly black precipitate and a brown- black liquid. Several experiments were made to determine what agents caused the change. The hydrogen dioxide gly- cerin, and water showed no change on standing several days but when a mixture of these contained zinc sulphate it ac- quired a yellow to a yellow-brown color and became turbid after a day or two. A mixture of carbolic acid, hydrogen dioxide, and water showed no change after standing several days, but as soon as zinc sulphate was added a play of colors was noticed. There was first a green, then green-black, brown-black, red-brown, red-brown with a tinge of purple, finally brown-black, all within a space of a few minutes. In less than a half hour a precipitate had formed which increased on standing. On adding a solution of zinc sulphate to hydro- gen dioxide water an effervescence took place and gas was formed slowly for several hours; a light precipitate settled. Hydrogen dioxide is said to oxidize carbolic acid to pyro- catechin and hydroquinone and to oxidize glycerin to gly- ceric, oxalic, and tartaric acids. Just what part the zinc sul- phate played in this prescription was not determined. It per- haps acted only as a carrier or perhaps as a decomposer of the hydrogen dioxide. 111. This mixture is permanent in a dry atmosphere, but in a damp one it absorbs moisture. Either in the presence of absorbed moisture or when taken into the stomach several reactions are liable to take place. Lead sulphate would be formed from the lead subacetate and morphine sulphate. The sodium bicarbonate would react with each of the other three ingredients, forming with bismuth subnitrate, bismuth subcarbonate and carbon dioxide; with lead subacetate. lead INCOMPATIBILITIES IN PRESCRIPTIONS. 195 carbonate; with morphine sulphate, the free alkaloid. Lead subacetate would also combine with the morphine to make a compound insoluble in water. These incompatibilities do not make a dangerous mixture, and there is no reason for declining to fill it. 112. Triturating the iodol with the mercuric oxide caused an explosion, which might have been avoided by mixing the ingredients separately with portions of petrolatum and then mixing these. 113. A mixture of these ingredients sometimes becomes soft and sticky in a short time and again it may remain in a powder for days. The condition of the atmosphere seems to cause the variation. " The reaction between sodium salicylate and antipyrin, thought to be due to chemical change, is simply due to deliquescence." (Nat. Dispensatory, 5th ed., 227.) This explanation is hardly satisfactory, since either cliemical alone is not hygroscopic. By putting these ingredients into capsules separately without previous mixing they in time become soft and liquid, but not before the prescription would ordinarily be used. The capsules might be dispensed in a bottle. 114. This was filled by dissolving the sodium bicarbonate, borax, salicylic and benzoic acids in water. The thymol and menthol were rubbed together until a liquid resulted; then the eucalyptol, the glycerin, and the oil of wintergreen were added. To this was added the first solution and an efiferves- cence ensued. After allowing the mixture to stand an oily liquid separated, rising to the top. The effervescence is due to a reaction between the bicarbonate and the salicylic. 196 INCOMPATIBILITIES IN PRESCRIPTIONS. benzoic, and boric acids, the latter acid being formed by the action of glycerin on borax. (See No, 141.) Eucalyptol makes a clear mixture with glycerin, but is separated on the addition of water. The oily liquid formed by the menthol and thymol does not make a clear solution with glycerin, nor does the oil of wintergreen; and whatever of these may have been dissolved by the glycerin is thrown out of solution by the water. A '' Shake " label is necessary. 115. The quinine sulphate was dissolved in a part of the water with the aid of the acid. The potassium iodide was dissolved in the balance of the water and added to the quinine solution. Iodine is gradually formed by the acid acting on the iodide, and this combines with the quinine, forming a dark-brown precipitate. 116. Basham's mixture contains acetic acid and an acetate. The quinine salt dissolves in this, but within a few minutes it is thrown down as a bulky crystalline quinine acetate. The mixture is so thick that it would be difficult to pour out an even dose. 117. Borax is alkaline in reaction and precipitates the hydras- tine as the free alkaloid, and also precipitates the alkaloids from the tincture of opium. The boric acid is not sufficient to neutralize the alkalinity of the borax. As the preparation is to be dropped into the eye. it should be filtered, and in so doing nearly all of the hydrastine is removed. The physician's attention should be called to this, and he be advised to in- crease the amount of acid or decrease the borax or. what is better, leave out the latter. Boric acid does not give a pre- cipitate with a solution of hydrastine sulphate. INCOMPATIBILITIES IN PRESCRIPTIONS. igj 118. When these ingredients were mixed a clear solution resulted, which was of a light-yellow color at first, but within five minutes became green. On allowing this to stand no change in color took place until the third or fourth day, when it acquired a greenish-brown color, and by the sixth day it had lost all green and was of a brownish-red color; further standing changed it to a deep red. It has been proved that ethyl nitrite or amyl nitrite or any substance containing nitrous acid forms with antipyrin the green isonitroso-antipyrin, which crystallizes out of con- centrated solutions. At one time it was thought that this green compound was poisonous, but it is not now generally considered so. [See Antipyrinum, No. 17.] 119. The quinine sulphate was dissolved in part of the water with the aid of the acid. When the solution of potassium iodide in the balance of the water was added to the quinine solution a prcipitation occurred. This granular precipitate, which falls quickly, is potassium bitartrate, formed by the reaction between the potassium iodide and the tartaric acid. That it is not the quinine that is precipitated can be proved by substituting sodium iodide for potassium iodide, when no precipitation takes place. In concentrated solutions potas- sium iodide precipitates quinine. Hydriodic acid, formed by the action of tartaric acid on potassium iodide, is easily decomposed by the air, liberating iodine which precipitates the quinine. When this mixture is allowed to stand for two or three weeks without being disturbed two layers in the pre- cipitate are noticed, the bottom one is white and is the potas- sium bitartrate, while the upper one is red-brown and is the iodine compound of quinine. The directions are: Mix. Label: Let a teaspoonful be taken two or three times a day. 198 INCOMPATIBILITIES IN PRESCRIPTIONS. 120. When the spirit of nitrous ether is added to the resorcin dissolved in the water and glycerin a dark-red solution is formed. This is perhaps due to the formation of dinitroso- resorcin (or possibly mononitroso-resorcin), which crystallizes in yellowish plates. Ammonia turns this solution a deep blue. 121. When first mixed the solution is clear and colorless, but changes in a day or two to a blue. This on standing for two or three weeks becomes dark purple or violet-blue. 122. These ingredients make a clear dark-red solution, which changes to a red-straw color within five minutes. The red color is due largely to the tincture of iodine. Iodine with ammonia in excess forms chiefly ammonium iodide with a little ammonium iodate, so that in this prescription, so far as physiological effect is concerned, it would be about as well to use some ammonium iodide instead of tincture of iodine. At the end of twenty-four hours the mixture was strong-ly alka- line and still slightly colored. In a mixture of ammonia and iodine there is some danger of the violently explosive iodide of nitrogen being formed, more especially where the iodine is in excess. This iodide of nitrogen is insoluble and is slowly precipitated as a dark- brown solid. 123. This prescription makes at first a clear solution, which gives a precipitate on standing for a few hours. If the tinc- ture of iron is not strongly acid the precipitate is yellowish brown. The precipitate was filtered out and washed with water until the washings no longer gave a test for iron. It was INCOMPATIBILITIES IN PRESCRIPTIONS. 199 then dissolved iti dilute sulphuric acid; the solution was not fluorescent nor bitter; on adding ammonia water it gave a heavy red-brown precipitate of ferric hydrate. From this it was supposed that the original precipitate was a basic salt of iron which had been thrown out of solution by the quinine taking some of the hydrochloric acid from the tincture to form a more soluble quinine salt. If, however, some hydrochloric acid is added to the tinc- ture before adding the alkaloidal salts the solution remains clear for some time, but finally deposits prismatic crystals. These crystals dissolve readily on addition of water, and are probably a quinine salt separated out from a supersaturated solution. The pharmacist in dispensing the prescription should see that the tincture is quite strongly acid. The physician should also give his consent to allow the solution to be diluted with water with an increase in the dose. 124. This solution is bluish red in color. No chemical reac- tion occurs except that the salicylic acid occurring as methyl salicylate in the oil of wintergreen combines with the iron to form a salicylate of iron, which gives the increase of color. By adding the water gradually to the iron a play of colors is noticed: first yellow, then red, dark red, and finally violet-red. 125. Salol and thymol triturated together make a liquid. When the other ingredients are added the mass is still much too soft to be made into pills. If a sufficient amount of liquorice root is added to make the mass of the required consistency the pills are too large to be taken easily. If the soap and extract of liquorice are omitted and in their place one dram of magnesia and one dram of kaolin are used a fair mass is made. Even then the pills are large and it is better to make twice the number of pills and double the dose. 200 INCOMPATIBILITIES IN PRESCRIPTIONS. 126. The spirit of nitrous ether acts on the morphine, giving^ a yellow color which becomes more of a brown on standing. Nitrous acid converts morphine into nitroso-morphine. pseudo-morphine, and another base (M. & M., iii. 436). The directions are: Mix. Label: Take a teaspoonful as often as is required. 127. Several reactions may occur when the first two ingredi- ents are mixed, depending upon the proportions. A mer- curic oxychloride is formed by the carbonate of potassium in the Fowler's solution. Under certain circumstances mercuric arsenite is formed and is dissolved in a solution of potassium arsenite. In the presence of an alkali, arsenites reduce mercuric compounds to mercurous compounds and then to metallic mercury, and the arsenites are oxidized to arsenates. In this prescription a pinkish-white precipitate is first formed, consisting of calomel and the coloring matter of Fowler's solution. On further standing it turns dark, due to the reduction to metallic mercury. Fowler's solution added to the quinine sulphate liberates the free alkaloid. If the prescriber had directed the solution of arsenous acid instead of potassium arsenite there would have been no re- duction and but little precipitation. 128. The ammonia water combines with the acid in the tinc- ture of iron, forming ammonium chloride and ferric hydrate. The precipitation of the ferric hydrate may be prevented by mixing the glycerin with the tincture before adding the am- monia. If the ammonia is added to the tincture and then the glycerin the precipitated ferric hydrate dissolves but slowly in the glycerin. Glycerin, as well as sugar, acacia, honey, and some other organic substances, prevents or hinders the pre- cipitation of many of the metals by alkali hydrates. INCOMPATIBILITIES IN PRESCRIPTIONS. 20T 129. Ferric salts gelatinize mucilage of acacia, and if the solu- tion of dialyzed iron is added directly to the mucilage a solid mass results, which dissolves slowly in the syrup. By diluting the solution of iron with the syrup, and then adding this slowly to the mucilage with constant stirring, a thick homo- geneous liquid may be obtained. [See Acacia, Nos. h and 3.] 130. " According to M. Mialhe, calomel is partly converted into corrosive sublimate and metallic mercury by ammoniuiTi chloride and by sodium and potassium chlorides, even at the temperature of the body." (U. S. Dispensatory, 17th ed., 695.) This is not now generally considered a dangerous, prescription. [See Hydrargyri Chloridum Mite, No. 7.] The directions are: Mix and divide into 20 equal parts. Label: Take one two or three times a day. 131. Spirit of nitrous ether with acetanilid gives a yellow solu- tion, becoming red on standing for some time. The color occurs more quickly with an acid spirit than with a neutral one, and the presence of a little sodium bicarbonate prevents, it for several weeks. Probably diazo-compounds are formed. 132. Amyl nitrite and potassium iodide in the presence of an acid give free iodine, nitric oxide, and amyl alcohol. The prescription should not be dispensed as written. As from the directions — " Let it be dispensed quickly " — it seems to be an urgent case, and in all probability the efifect of the amyl nitrite is what is wanted, the potassium iodide should be omitted. At the very first opportunity the physician should be informed of the omission. 202 INCOMPATIBILITIES IN PRESCRIPTIONS. 133. The first three ingredients were mixed and the Epsom salt dissolved in the water and the two solutions mixed. A turbidity occurred at once, due to the precipitation of ex- tractive matter from the alcoholic liquids by the water. Within a few hours the magnesium sulphate had crystallized out so that its bulk was nearly one half of that of the mixture. Magnesium sulphate, being insoluble in alcohol, is thrown out of its aqueous solution by the alcohol of the fluid extracts ■and the tincture. This cannot be prevented except by diminishing the magnesium sulphate or increasing the pro- portion of water. If the mixture is made up to one pint with water the magnesium salt is not thrown out of solution. 134. Iodine is soluble in lo parts of alcohol and 6o parts of glycerin; nearly insoluble in water. The first two in- gredients mix, making a clear solution, but water precipitates the iodine unless an old tincture of iodine which contains some hydriodic acid is used. By adding three or four grains of potassium iodide to the water the iodine remains in solu- tion. Such an addition is admissible and should be made. 135. The solution of bismuth (National Formulary) contains bismuth and ammonium citrate dissolved in water and am- monia water. Wine of pepsin (N. F.) contains hydrochloric acid. If the acid in the wine is in excess of the ammonia bismuth citrate will be precipitated. If the ammonia is in excess of the acid the pepsin is rendered inert. Some ex- tractive matter in the tincture will be precipitated by the water. In filling this prescription the ingredients should be made as nearly neutral to litmus paper as possible before mixing. INCOMPATIBILITIES IN PRESCRIPTIONS. 203 136. When calomel and cocaine hydrochloride are triturated together a gray mixture results. Probably a part of the calomel is reduced to metallic mercury, which gives the gray color, and another part is oxidized to mercuric chloride. As the amount in each pill of the mercuric chloride formed is within the limits of the dose of that substance, the pills may be dispensed. It would be well, however, to inquire the age of the patient and the frequency of the dose. By the addi- tion of about five grains of starch or liquorice root and a little water a suitable pill-mass can be made, the pepsin giving .sufficient adhesive qualities. 137. This is a very common combination. Lead subacetate forms compounds with nearly all alkaloids, and these are in- soluble in water. The opium alkaloids are no exceptions. The alcohol undoubtedly tends to prevent the precipitation to some extent, though there is still quite a heavy one. The lead is also precipitated by the meconic and sulphuric acids in the opium. The precipitate should not be filtered out but the mixture should be dispensed with a " Shake well " label. 138. The usual dose of the fluid extract of digitalis is o.oi to 0.12 Cc. In this prescription it is about 0.24 Cc, which is so largely in excess of the usual dose that the pharmacist should satisfy himself that the physician has made no mis- take. The water gives a precipitate with the fluid extracts. If the spirit of nitrous ether is mixed directly with the fluid extracts it reacts with the tannin, giving off fumes of nitric oxide. 139. When silver oxide and creosote are triturated together there is great danger of an explosion. It has been proposed 204 INCOMPATIBILITIES IN PRESCRIPTIONS. to mix the creosote with powdered soap and then with the oxide, which has been previously mixed with Hquorice root. The mass should not be rubbed hard and should be kept cool. 140. The tannic acid in the tincture combines with the quinine to make the insoluble nearly tasteless quinine tannate. The water precipitates the resinous matter from the tincture. A " Shake well " label should be put on the bottle, 141. In filling this prescription there will be an effervescence, due to the generation of carbon dioxide. It is not caused by the carbolic acid and sodium bicarbonate, as might be sup- posed. Glycerin in the presence of water decomposes borax, forming sodium metaborate and boroglycerol. Water reacts with the boroglycerol to give glycerin and boric acid. The boric acid with sodium bicarbonate gives sodium borate and carbon dioxide. Other polyhydric alcohols, such as manni- tol, dextrose, levulose, and glucose, act like glycerin in de- composing borax. The chemical reactions which take place may be represented by the following equations: Na2B,07-f2C3H5(OH)3 = 2C3H5B03-f-2NaB02 + 3H20; C3H5BO3 + 3H2O = C3H,(OH)3 + H3BO3; H3BO3 + sNaHCOg = Na3B03 + 3CO0 + 3H2O. 142. Carbon dioxide will be generated by the sulphuric acid and the potassium bicarbonate. There is a sufficient amount of the bicarbonate to neutralize all of the acid and also ta liberate quinine as free alkaloid, which is nearly insoluble. It will also liberate ammonia from the ammonium carbonate in the aromatic spirit of ammonia used as the menstruum in making the tincture. Resinous matter and the oils in the INCOMPATIBILITIES IN PRESCRIPTIONS. 205 tincture are thrown out of solution by the water. Tincture of guaiac if freshly prepared colors acacia blue. 143. Spirit of turpentine is another name for oil of turpentine. Oil of turpentine is easily oxidized and nitrohydrochloric acid is a strong oxidizing agent, so that there is cjuite a violent reaction when the two are brought together. Even though the oil is emulsified first, chemical change cannot be avoided. Supposing that the prescriber wanted a four-ounce mixture,, the dose of the acid would be about thirteen minims. The maximum dose, as given in the U. S. Dispensatory, is six drops. The excessive dose would be sufficient to prohibit the filling of this prescription. In such a case where the pre- scriber could not be notified many pharmacists would use the dilute nitrohydrochloric acid instead of the concentrated. 144. The potassium permanganate was dissolved in part of the water and the glycerin was diluted with the balance of the water; the two solutions were then mixed. Within two minutes the mixture was of a brownish-black color and al- most solidified by the manganese dioxide that was formed. After standing the precipitated manganese dioxide settled, leaving a clear colorless solution, showing that the perman- ganate was all reduced. When potassium permanganate and concentrated glycerin are brought together there is some liability of the mixture exploding or inflaming. The oxida- tion products of the glycerin are probably formic, propionic,, and tartronic acids; in an alkaHne mixture oxalic and car- bonic acids are formed. 145. The potassium citrate was dissolved in the syrup and the spirit was then added. The two liquids were mixed, produc- 2o6 INCOMPATIBILITIES IN PRESCRIPTIONS. ing a turbidity, and on standing separated into two distinct layers. Potassium citrate is hygroscopic, but nearly insolu- ble in alcohol. The alcohol of the spirit has a tendency to throw the citrate out of solution, but the salt has such an affinity for water that it carries some water with it, forming a solution not miscible with alcohol. 146. The aromatic spirit of ammonia contains ammonium hydrate and ammonium carbonate, and these act similarly in precipitating the corrosive sublimate as ammoniated mercury (NHoHgCl). Ammoniated mercury is soluble in solutions of ammonium salts and somewhat soluble in acids, so that the sulphuric acid in the infusion will redissolve it, though not very readily. The precipitation may be prevented by mixing the infusion and spirit together first. Mercuric chloride pre- cipitates the cinchona alkaloids from their aqueous solutions when not too dilute. The oils in the spirit are thrown out of solution by the water of the infusion. The directions are: Mix. Label: Teaspoonful twice a day. 147. Triturating the alum with the lead acetate produces a moist sticky mass. This is due to the chemical reaction which takes place, forming lead sulphate, aluminum sulphate, potassium acetate, and liberating the water of crystallization which makes the mixture sticky. A mass is obtained when zinc sulphate and lead acetate are rubbed together. In either case the odor of acetic acid is noticeable. When the mixture is put into water the tannic acid will precipitate the lead, if any remains not combined with sulphuric acid, as lead tan- nate. The other two salts are not so readily precipitated as tannates. In filling this prescription the water of crystalliza- tion may be removed by heating, or the ingredients may be powdered separately and then mixed lightly, and no difficulty will ensue. INCOMPATIBILITIES IN PRESCRIPTIONS. 207 148. The difficulty with this prescription is that triturating the salicyHc acid with the exalgin produces a soft sticky mass which is unfit for dispensing in powders. Even by mixing all of the other ingredients except the acid and adding it last and then mixing lightly on paper the mixture becomes sticky. By diluting the acid with twice its weight of pow- dered althea and then with the other ingredients a fair powder can be obtained. Probably the best way would be to put the ingredients into capsules, separating the acid from the exalgin by the phenacetin and cocaine, if the mixture is to be used internally. 149. This makes a mixture which is very thick at first, but yet can be poured. Allow it to stand for half an hour and it solidifies; by the end of twelve hours it is so firm that it can- not be shaken in the bottle. Even if only one half of the amount of magnesia is used the mixture will solidify so that it cannot be shaken up if allowed to stand undisturbed for a day or two. By vigorous shaking several times the mass can be broken up so that it can be poured. Magnesium oxide takes up water to form the gelatinous magnesium hydrate. The alkalies all tend to prevent the precipitation of the resin- ous matter in the tincture by the water. 150. Several chemical reactions will take place, depending upon the order of mixing. The possible reactions are as fol- lows: I. Ferric iron is reduced to ferrous iron, giving at first a red solution of ferric sulphite. 2. The hydrochloric acid of the tincture reacts with the hyposulphite, forming sodium chloride, sulphurous acid, and sulphur. 3. With potassium chlorate, the sulphurous acid thus formed gives potassium sulphate, hydrochloric and sulphuric acids. 4. Hydrochloric 2o8 INCOMPATIBILITIES IN PRESCRIPTIONS. acid with potassium chlorate gives potassium chloride, water, chlorine, and several oxides of chlorine. 5. The chlorine thus formed oxidizes the reduced ferric salt back to the ferric con- dition and oxidizes the hyposulphite to a sulphate. There is not enough water to dissolve all of the chlorate, and after the reactions have taken place there is not enough acid to form a normal ferric salt of all of the iron; a part of it remains as an insoluble oxychloride. 151. When phenacetin and quinine sulphate are triturated to- ■gether no change is noticed, but on adding hydrobromic acid the mixture acquires a yellowish-green color. What reaction occurs has not been determined. Phenacetin and hydro- bromic acid give a white mixture; quinine sulphate and hydrobromic acid give only a very slight greenish color. An- other incompatibility is between the hydrobromic acid and the calomel; a part of the mercurous chloride is reduced to metallic mercury, and a part is oxidized to mercuric chloride, which is much more active than calomel. By adding the calomel last the reaction can be prevented to some extent, but it may even then be considered as a rather dangerous mixture. The directions are: Mix and divide into 10 equal parts and put into gelatin capsules. Label: One capsule to be taken every three hours. 152. Commercial dilute hydrocyanic acid usually contains some free sulphuric or hydrochloric acid, which has been added to preser\'e the hydrocyanic acid. If one of these mineral acids is present an effervescence will take place. Hydrocyanic acid itself does not decompose carbonates (Prescott and Johnson's Qualitative Chemical Analysis, 4th ed., 308). Hydrocyanic acid easily decomposes in water, but in an alkaline solution its decomposition is much quicker, giving INCOMPATIBILITIES IN PRESCRIPTIONS. 209 a formate and a dark-colored precipitate containing para- cyanogen. 153. Triturating salol and monobromated camphor together produces a Hquid. But if the acetanihd and salol are rubbed together first and then the camphor added a damp powder is obtained. If about fifteen grains of powdered soap are then added and a little drying powder if necessary, a mass can be made, the pills becoming hard in an hour or two. 154. The order of mixing these ingredients makes a difference in the products first formed, but after standing the results are probably similar. If the solution of zinc chloride and the lime water are mixed a white precipitate of zinc hydrate is formed, and there is no change in appearance on adding the mercuric chloride dissolved in the water. If, however, the mercuric chloride solution is added to the lime water the yellow oxide of mercury (yellow wash) is precipitated. On adding the zinc chloride solution and al- lowing it to stand the precipitate is changed within two hours from a dense yellow to a fiocculent white precipitate. If the lime water is added to the solution of mercuric chloride a red-brown precipitate of oxychloride of mercury is formed, and this is replaced by a white precipitate when the zinc chloride is added. That the lime water precipitates nearly all of the mercuric chloride when these two chemicals are brought together in the above proportions is evidenced by taking some of the clear supernatant liquid and passing hydrogen sulphide gas through it and getting little or no black precipitate of mer- curic sulphide. If some of the clear solution is taken after the zinc chloride has been added and the yellow precipitate turned white, and this solution is treated with hydrogen sul- phide, a heavy black precipitate of mercuric sulphide is pro- 2IO INCOMPATIBILITIES IN PRESCRIPTIONS. duced, showing that the mercuric oxide has been dissolved and the zinc precipitated. Owing to the fact that the mer- cury is in solution, this prescription might be considered dan- gerous for application, since if all of the mercury is redissolved it will be in the proportion of about i to 500. 155. Piperazin is strongly alkaline and when added to an aqueous solution of phenocoll hydrochloride precipitates the insoluble base phenocoll. Under certain circumstances, as when the phenocoll hydrochloride is from fifty to one hun- dred per cent, in excess of the piperazin, a clear solution is said to be obtained. This prescription was filled by dissolving the phenocoll hydrochloride in the elixir, syrup, and pepper- mint water, and the piperazin in the water. The two solu- tions were mixed, making a clear solution, which remained clear for two days. It then happened to be chilled at night and crystallization took place, making an almost solid mass., which remained so even at the ordinary temperature. On warming a solution resulted, which remained clear at the ordinary temperature, but again solidified on being chilled. 156. The ammoniated tincture of guaiac if it has not been ex- posed too long to light and air gives a blue color with the tincture of iron, but an old tincture of guaiac gives a brown- black. The tincture of aloes gives a green-brown to a black- brovk'n with the iron. There is not enough of ammonia in the ammoniated tincture of guaiac to form the ferric hydrate un- less the tincture of guaiac is freshly made with a fresh aro- matic spirit of ammonia and the tincture of iron is free from excess of acid. Even then the syrup will tend to keen the ferric hydrate in solution. The syrup precipitates the resin- ous matter from both tinctures. The resulting mixture is. nearly black and very turbid. INCOMPATIBILITIES IN PRESCRIPTIONS. 211 157. The dose of the morphine sulphate is considerably in excess of the amount usually given. The prescriber shows his knowledge and appreciation of this fact by putting three exclamation-points after the ingredient. The prescription should be filled as written. Some physicians when wishing to give unusual doses underscore the ingredient and the quan- tity. The latter is perhaps a better method, as there is less danger of a mistake. The directions are: Mix. Dispense in 10 capsules. Label: Let one be taken during the night. 158. On mixing these ingredients a blue-black solution is ob- tained. This is due to the presence of some ferric sulphate. Ferrous sulphate as found in drug-stores nearly always con- tains some ferric sulphate. If strictly ferrous sulphate is used tannic acid gives no coloration with it. This prescription was filled by dissolving the clear crystals of ferrous sulphate in water, adding four grains of sodium thyosulphate and two drops of sulphuric acid, and boiling until all of the ferric iron was reduced to the ferrous, as shown by adding a drop of this solution to a solution of potassium sulphocyanide and getting no red color. The tannic acid was dissolved in another portion of water, the syrup added, and this added to the iron solution. A colorless liquid was obtained, astringent but not inky in taste. In three days the solution had assumed a green color and in ten days it was blue-black. This change, caused by the oxidation of the iron by the air, would have taken place sooner if the bottle had been opened frequently. 159. This prescription can be filled in one of two ways. The chloral hydrate may be dissolved in the water, and the cam- phor powdered and mixed with the syrup and then with the ■212 INCOMPATIBILITIES IN PRESCRIPTIONS. solution of chloral. The camphor will rise to the top. Or the camphor may be triturated with the chloral hydrate until liquefied, and this shaken with the syrup and water. The oily chloral-camphor does not dissolve in the water, but seems to be decomposed by it, the chloral going into solu- tion and the camphor coming to the top as a soft white solid. There seems to be no difference in the final result as to which method of filling is used. In either case the mixture is a difficult one to pour so as to get an even dose of the camphor. A more elegant preparation would be made by dissolving the camphor in a little expressed oil of almonds and then emulsifying it with acacia. 160. On adding the phosphoric acid to a solution of the iron and quinine citrate a white precipitate forms which gives tests for iron but not for quinine. It is prob- ably iron phosphate and is soluble in a considerable ex- cess of the acid. When the dilute phosphoric acid is further diluted with water and then added to the iron salt dissolved in the balance of the water with the syrup, little or no pre- cipitation takes place. When the tincture is added to this. a turbidity results and the mixture becomes darkened, due to the precipitation of matter from the tincture and the for- mation of tannate of iron. 161. In lightly mixing the first two ingredients when powdered and perfectly dry no change in color is noticed; triturated together with considerable pressure, the powder turns gray. As soon as moisture comes in contact with the mixed pow- ders they become dark gray — the coloration is due to the formation of metallic mercury — while at the same time a part of the calomel is changed to mercuric chloride and mercuric cyanide. The prescription should not be dispensed. (See No. 192.) A translation of the latter part of the prescription INCOMPATIBILITIES IN PRESCRIPTIONS. 213 is: Tragacanth, water, of each a quantity sufficient to make a mass which is to be formed into 30 pihs. Label: Take two pills every night. 162. Soluble metallic salts frequently throw the volatile in- gredient of medicated or aromatic 'waters out of solution. In this case there will be a separation of camphor, which will rise and float on top. The amount is so small that it may be disregarded or filtered out. 163. The Rochelle salt throws some of the camphor out of solution. Then on the addition of the aromatic sulphuric acid the turbidity is increased on account of the separation of the oil of cinnamon and the resin of ginger. Chemical reaction takes place between the Rochelle salt and the sul- phuric acid, the sodium sulphate going into solution and potassium bitartrate being precipitated. 164. Fowler's solution is alkaline in reaction and has a ten- dency to precipitate the alkaloids from the fluid extract, but this is prevented by the alcohol in the elixir. The Fowler's solution contains some carbonate and bicarbonate of potas- sium, which are said to be incompatible with antipyrin. Am- monium iodide generally contains a little free iodine, and iodine combines with antipyrin. Practically, however, this prescription can be filled without difficulty or danger. 165. Strychnine (free alkaloid) is soluble in 6700 parts of water. There is enough of water and alcohol in the elixir to prevent the aromatic spirit of ammonia from throwing it out of solu- tion. The ammonia will not precipitate the alkaloids of the 214 INCOMPATIBILITIES IN PRESCRIPTIONS. elixir of cinchona. The above mixture will not be clear, how- ever, because the oils in the aromatic spirit will be separated by the elixir. If the spirit of ammonia were used instead of the aromatic spirit a clear dark-red solution would be ob- tained. This substitution would not be allowable without the prescriber's consent. 166. All of the ingredients except the syrup can be mixed without producing much turbidity. But on adding the syrup to this mixture the resinous matter from the fluid extract and tincture is precipitated, and the copaiba, oil of turpentine, and camphor are separated. To make a present- able mixture some emulsifying agent must be used. 167. " On adding carbolic acid to albumin or to collodion coagulation takes place (difference from creosote)." (U. S. P., 9.) This mixture makes a solid mass and cannot be applied with a brush. A gelatinous mass which possibly might be applied with a brush is obtained when one half of the collodion is replaced by alcohol. 168. If the Fowler's solution is added to the tincture of nux vomica the alkali in the solution will liberate the free alkaloid strychnine, but it will be held in solution by the alcohol until the infusion is added. With the addition of most infusions the alkaloids would be precipitated, but the infusion of cin- chona contains sulphuric acid, which combines with the alkaloids, forming a soluble salt. The water of the infusion will precipitate some of the inert matter from the tincture. 169. When solution of lead subacetate is added to mucilage of acacia a solid gelatinous mass is formed. In this prescrip- INCOMPATIBILITIES IN PRESCRIPTIONS. 215 tion if both are diluted with the water and mixed with con- stant stirring the acacia is precipitated in small masses. Neutral lead acetate does not gelatinize mucilage of acacia. 170. The silver nitrate is entirely precipitated by the sodium chloride as silver chloride. It is customary to filter eye- washes, and if this one is filtered there will be only a very weak solution of sodium chloride and sodium nitrate left. There is no admissible method by which the precipitation can be prevented without changing the prescription. 171. If concentrated solutions of the first two ingredients are mixed a reddish-brown salicylate of iron is precipitated. The citric acid in the syrup of lemon precipitates salicylic acid from a concentrated solution of lithium salicylate. By dissolving the iron salt in a part of the water and adding the syrup, then dissolving the salicylate in the balance of the water and mixing the solutions, a clear deep-red solution can be obtained. The deep-red color is due to the ferric salicylate formed, 172. The calcium hypophosphite slowly reduces the mercuric chloride to mercurous chloride and finally to metallic mer- cury. This precipitation is not readily seen in the syrup of sarsaparilla, but if water is used instead of the syrup a tur- bidity is noticed as soon as solutions of the salts are brought together. The syrup of sarsaparilla also has a tendency to reduce the corrosive sublimate, but only very slowly. 173. The maximum dose of santonin, as given by most authori- ties, is four grains, some giving as high as five grains. Hav- 2i6 INCOMPATIBILITIES IN PRESCRIPTIONS. ing two maximum doses coming so close together renders this prescription a dangerous one. Prescriptions containing santonin should be protected from the light, as light causes a change in color from white to yellow, probably with the formation of new compounds. Inquiry should be made to determine whether it is for a child or an adult and if for the former the prescription should not be filled, as two grains are said to have killed a child. 174. This mixture is far from being a solution. The benzoin and the Tolu are only partially soluble in alcohol and the acacia is insoluble. The insoluble matter quickly settles to the bottom of the mixture, forming a layer nearly equal in depth to that of the supernatant liquid. It, however, may be readily dififused through the liquid by agitation. A " Shake well " label is necessary, 175. A clear solution is formed at first, but in about a half hour needle-shaped crystals begin to fall. The precipitate in- creases for several hours and contains strychnine which is thrown out of solution with the iodide. Much commercial potassium iodide contains a carbonate, but in this case an iodide free from carbonate was used. It has been suggested to use acacia to suspend the precipitate, but this is.objection- able because the mixture liberates iodine on standing a few days and iodine further precipitates strychnine. Mucilage of acacia is acid and probably sets free some hydriodic acid which is oxidized by the air. 176. Borax is alkaline in reaction and precipitates nearly all alkaloids from solutions of their salts. It precipitates the cocaine in this prescription, but the difficulty can be pre- INCOMPATIBILITIES IN PRESCRIPTIONS. 217" vented by the use of a little glycerin. The glycerin acts chemically on the borax, breaking it up and forming sodium metaborate and boric acid. (See No. 141.) If boric acid were used instead of borax no precipitation would occur. 177. Both the ammonium carbonate and the ammonium hy- drate precipitate the mercuric chloride as nitrogen dihydro- gen mercuric chloride, known in commerce as " ammoniated mercury " or " white precipitate." The precipitate settles quickly, but does not leave a clear fluid. The water of the mercuric chloride solution throws the oils of the aromatic spirit out of solution, making a white milky mixture. 178. When the sodium salicylate dissolved in a little water is added to the quinine sulphate dissolved in the balance of the water with the aid of the hydrobromic acid, a curdy sticky precipitate is formed that cannot be mixed with the liquid. Two chemical reactions take place. Sodium salicylate with quinine sulphate forms sodium sulphate and the nearly insolu- ble quinine salicylate. Hydrobromic acid with sodium salicy- ate forms sodium bromide and the nearly insoluble salicylic acid. Permission to use alcohol or some other solvent should be obtained. 179. On mixing solutions of the first two ingredients a reac- tion takes place, with the formation of free iodine and a reddish-brown precipitate. The aqueous solution of iron and quinine citrate is acid, and ferric salts in acid solutions with potassium iodide are reduced to ferrous compounds, iodine being liberated. Iodine in an aqueous solution of potassium iodide is a general alkaloidal reagent and precipitates the 21 8 INCOMPATIBILITIES IN PRESCRIPTIONS. quinine. Neutralizing the solution will prevent liberation of iodine for a time. 180. This prescription is frequently given as an example of the incompatibility of bromides with strychnine salts. It is said that crystals of strychnine bromide will form after the mix- ture has been standing for a half hour. The writer failed repeatedly to get a precipitate even on making the solution twice as strong as that called for and also varying the propor- tions. The precipitation is partially explained by some writers by saying that the strychnine bromide is soluble in water, but insoluble in a solution of potassium bromide. In many instances the commercial potassium bromide is alka- line, due to the presence of a carbonate which has been left in to aid the preservation of the bromide. The carbonate precipitates the strychnine as the free alkaloid. 181. Although the Fowler's solution is alkaline, there is enough of acid in the prescription to prevent any precipitation by it. The insoluble ferric phosphate is thrown down. By using the tincture of citro-chloride of iron no precipitation results at once but does after a day or two. If it were admissible to use twice as much phosphoric acid as tincture of iron there would be no precipitation. 182. The National Dispensatory (5th ed., 826) says of calomel: " Boiling hydrochloric acid dissolves mercuric chloride and leaves mercury; in the diluted state and heated in contact with air mercuric chloride is slowly dissolved without separa- tion of mercury." And again: "According to Jolly's ob- servations, corrosive sublimate is also formed from calomel in the presence of hydrochloric acid." INCOMPATIBILITIES IN PRESCRIPTIONS. 219 It is a somewhat disputed question whether in such a prescription there would be any mercuric chloride formed, and if so whether the amount formed would be sufficient to have any disagreeable physiological effect. If the prescrip- tion is to be used up in a short time probably no bad results would follow. [See Hydrargyri Chloridum Mite, No. 7.] 183. Terpin hydrate dissolves in about 250 parts of water and iodol in about 5000 parts of water. These should be finely powdered before mixing with the other ingredients, and the prescription dispensed with a " Shake well " label. The glycerin and syrup are sufficiently viscid to keep the insoluble substances in suspension for a time. 184. Each ingredient should be powdered separately and then mixed lightly with the other. If the two are rubbed together with some force slight crackling explosions take place. A sharp blow would probably cause serious results. The patient should be cautioned. With a little care on the part of the pharmacist and patient no ill results will follow from this combination. 185. In this mixture the menthol floats on top and the boric acid goes to the bottom. Using alcohol, glycerin, or a fixed oil instead of water will not make a clear solution. The at- tention of the physician should be called to this prescrip- tion. 186. Santonin is soluble in about 40 parts of alcohol, nearly insoluble in water, and not readily soluble in turpentine. The amount prescribed is not all soluble in the mixture. The 220 INCOMPATIBILITIES IN PRESCRIPTIONS. turpentine does not mix, but floats on top. Extractive mat- ter from the fluid extracts is precipitated. The santonin, should be in the form of a fine powder and the mixture made. into an emulsion. 187. The potassium carbonate is deliquescent. It should be powdered with some absorbent powder, such as althea, and then the arsenic, previously triturated v^ith some sugar of milk, added. Next add the mass of iron and if necessary a little water. The pills should be dispensed in a bottle pro- tected from the atmosphere; otherwise they will become soft, 188. This solution has a much larger proportion of active in- gredients than is usually prescribed in an eye-wash. Probably the prescriber meant grains instead of drams. It should not be dispensed without consulting the physician, as it would probably cause intense irritation. In case the prescriber can- not be reached and it seems urgent that the prescription should be filled the quantities can be reduced to grains and the prescriber notified at the earliest opportunity. 189. Mixing a solution of silver nitrate with a solution of cocaine hydrochloride produces a white precipitate of silver chloride. If this is filtered out about one half of the silver is removed. The pharmacist should use cocaine nitrate. If he does not have it he can make it by dissolving the one grain of cocaine hydrochloride in a little water and adding one half a grain of silver nitrate in a little water. This makes cocaine nitrate and silver chloride. The precipitate can then be fil- tered out and the requisite amount of silver nitrate added. INCOMPATIBILITIES IN PRESCRIPTIONS. 221 190. Borax is soluble in 16 parts of water, and in this case there is not enough to dissolve it. Boric acid requires 25.6 parts of water to dissolve it, but it is much more soluble in a solution of borax. The principal difificulty with this prescrip- tion is that the mucilage of acacia is gelatinized by the borax, making a stiff mass. Boric acid has not the efifect of gelati- nizing acacia, and borax is prevented from doing so by the presence of sugar. Glycerin also prevents this action by de- composing the borax. 191. The first two ingredients are both disinfectants and oxi- dizing agents, yet they react on each other, with the reduciion of both. The chemical reaction is represented by the follow- ing equation: 2KMn04 + 5H2O2 + 3H2SO4 = 5O2 + 8H2O + K2SO4 + 2MnSO,- The sulphuric acid necessary for the reaction is present in the hydrogen dioxide water, as a small amount is allowed to remain for preservation of the dioxide. The amount of hy- drogen dioxide which 20 grains of potassium permanganate would act upon is 10.7 grains. If the dioxide water is offi- cial I fluid ounce contains about 13.7 grains of hydrogen di- oxide, which would be sufficient to reduce all of the perman- ganate and decolorize the solution. The directions are: Let them be mixed by vigorous shaking. Label: Let it be ap- plied to the affected parts night and morning. 192. The cherry-laurel water of the Br. P. contains o.i per cent, of hydrocyanic acid. It has been proved that calomel with hydrocyanic acid is changed to mercuric chloride, mercuric cyanide, and metallic mercury. Hydrocyanic acid displaces 2J2 INCOMPATIBILITIES IN PRESCRIPTIONS. hydrochloric acid in dilute solutions, while in concentrated solutions hydrochloric acid displaces hydrocyanic acid. There is such a small amount of hydrocyanic acid that there would not be much of the mercuric salts formed. 193. A mixture of thymol, alcohol, and ammonia is colorless at first, but acquires a decided though not deep green color on standing for a week. If the chlorinated soda solution is added to a mixture of thymol, alcohol, and ammonia a light- green clear solution is formed at once. Within ten minutes this becomes slightly turbid and of a deep-green color. On allowing it to stand a day an oily fluid separates from the dark-green solution in Httle round globules. These globules are black in appearance, but when broken up into very small ones they are blue-red or purple in color. This oily liquid has nearly the same specific gravity as the aqueous liquid. 194. When the cocaine is mixed with the solution of silver nitrate it gives a black precipitate of silver oxide. If the cocaine is first dissolved in water with the aid of a little dilute nitric acid, which converts the alkaloid into a salt, the solu- tion can be mixed with the silver nitrate without any pre- cipitation. A better method of filling would be to use the cocaine hydrochloride and follow the directions under No. 189. 195. This mixture gives at first a clear solution, but within a few minutes it begins to grow turbid from the production of a light-brown precipitate, which quite rapidly increases and becomes dark brown. This precipitation is due chiefly to the action of the eugenol in the pimenta on the tincture of iron. This is somewhat characteristic of all phenols, and INCOMPATIBILITIES IN PRESCRIPTIONS. 223 the color varies with the dilution. If the tincture of iron is not so very acid the quinine may precipitate some of the iron. 196. The quinine sulphate dissolves in the water and citric acid, making a clear solution that does not precipitate on standing. On adding the potassium citrate, crystals begin to separate at once. Adding more citric acid will dissolve the precipitate and the addition of another portion of potassium citrate causes a precipitation again. It is said that quinine acid citrate is formed. Whatever the precipitate is, it is probably thrown out of solution by making a concentrated solution of potassium citrate, although this does not entirely explain the result since acid clears up the mixture again. The direc- tions are: Mix. Label: A dessertspoonful after meals. 197. In the presence of moisture this mixture becomes black. The pilocarpine hydrochloride probably breaks up the cal- omel, forming mercuric chloride which combines with the alkaloidal salt, and metallic mercury which gives the mixture its dark color. Several of the alkaloids have that property. The directions translated into English are: Mix. Send 8 such powders. Label: Of these powders take one night and morning. 198. There is considerable danger in mixing these ingredients and the directions to " mix cautiously " should be followed. The potassium bichromate w^as powdered and mixed with the tar. To this the sulphuric acid was added with constant stirring. Heat and acrid fumes were generated. The mix- ture was a black, soft, granular mass, which after standing a day was scarcely acid to litmus paper. It probably had but little caustic effect. 224 INCOMPATIBILITIES IN PRESCRIPTIONS. 199. Sometimes the lime liniment causes a darkening when mixed with citrine ointment. In making the citrine ointment, if the nitric acid be insufficient in amount or the temperature rise too high, the oxidation of the fatty matter is effected in part at the expense of the mercuric nitrate, forming a mer- curous nitrate. The calcium hydrate in the lime liniment ^cts on the mercurous salt, forming the black mercurous oxide. A translation of the directions is: " Make an oint- ment, to be used as directed." I 200. The usual dose of the fluid extract of gelsemium is from two to three minims. In the above prescription it would be about twice this. When chloral hydrate and antipyrin are brought together in concentrated solutions in the right pro- portions an oily liquid separates and upon standing forms crystals of monochloral antipyrin, commonly known as hypnal. In this case there is more than enough of chloral for the antipyrin, the proper proportions being 47 Gm. of chloral to 53 Gm. of antipyrin. Possibly there may be some dichloral antipyrin formed in this prescription. At least there is a separation of an oily liquid that does not solidify. The resin- ous matter in the fluid extracts is precipitated by the water. The prescription should not be dispensed without consulting the prescriber. 201. Ferric acetate is formed in this prescription and it gives a very deep red color to the solution. If the ingredients answer the pharmacopoeial requirements there will be no in- compatibility. However, the solution of ammonium acetate is sometimes quite strongly alkaline, due to excess of am- monium carbonate or deficiency of acetic acid used; and if the tincture of iron is free from an excess of acid the alkali INCOMPATIBILITIES IN PRESCRIPTIONS. 225 causes the formation of ferric hydrate which will be kept in solution by the syrup. 202. As this prescription is written it would make a dangerous mixture. The solution of potassium arsenite, being alkaline, slowly precipitates the strychnine. If the solution of arsenous acid were directed instead of Fowler's solution there would be no danger and the physiological effect would be the same. 203. When the first two ingredients are rubbed together in a mortar chemical reaction takes place with enough violence to amount almost to an explosion, and there is an evolution of a large volume of white fumes. If the two chemicals are powdered separately and then mixed together lightly the change is slower and the mixture gradually turns brown. If mixed with separate portions of the cerate and then these mixed the reaction is retarded, but the ointment ultimately becomes brown. Chloral hydrate and potassium cyanide form dichloro-acetic acid, and in concentrated solutions form a crystalline compound which is not very soluble in water (M. & M., II. 4). 204. The quinine sulphate would not be entirely soluble even though there were no tannic acid in the infusion. The tannic acid converts the quinine sulphate into the less soluble quinine tannate. The oil in the spirit of rosemary is thrown out of solution, as well as some of the inert matter in the tincture. This is a poor combination, even for an external preparation. 205. By triturating the zinc oxide and carbonate with the petrolatum, and then adding the lime water gradually, a 226 INCOMPATIBILITIES IN PRESCRIPTIONS. partial emulsion can be effected. By the addition of thirty- grains of acacia an emulsion can be made, which soon separates into three layers, the bottom consisting of the zinc salts, the middle chiefly of water, and the top of the emul- sified petrolatum. These are readily mixed on agitation. Petrolatum is not saponified or otherwise chemically acted upon by calcium hydrate or other hydrates, as are the organic fixed oils and fatty substances. The best way to fill this prescription is to replace one fourth of -the petrolatum with lanolin, mix these with thirty grains of acacia and emulsify with about a dram of the lime water, then add the balance of the water and lastly the zinc oxide and carbonate. 206. Salicylic acid is soluble in 450 parts of water and 60 parts of glycerin; consequently a solution cannot be made unless something else be added. " With half its weight of borax and two and a half times its weight of glycerin a twenty-five per cent, solution of salicylic acid may be obtained." (Nat. Dispensatory, 5th ed., 89.) This prescription with thirty grains of borax would make a clear solution. But the addi- tion of borax, potassium nitrate, ammonium citrate, or sodium phosphate should not be made without the knowledge of the prescriber. In the absence of the physician this should be dispensed as a " Shake " mixture. 207. By mixing these ingredients a bright-red precipitate is formed in a few minutes and the iodine color of the liquid is nearly destroyed. In the course of a day or two there is no free iodine present. Probably three chemical reactions take place. The mercurous chloride and potassium iodide in the tincture form potassium mercuric iodide, potassium chloride, and metallic mercury. The metallic mercury with the iodine forms mercurous iodide, and this with more iodine makes INCOMPATIBILITIES IN PRESCRIPTIONS. 227 the red mercuric iodide. The final products depend to some extent upon the proportion of the tincture to the calomel. 208. The trouble with this prescription is to get into and to keep in solution the two alkaloidal salts. Cocaine hydro- chloride is soluble in .48 parts of water, 3.5 parts of alcohoU 2800 parts of ether, or 17 parts of chloroform. Morphine sulphate is soluble in 21 parts of water, 702 parts of alcohol, and nearly insoluble in ether or chloroform. The alcohol in the tincture is not present in sufficient amount to dissolve all of the morphine sulphate, and the ether and chloroform would throw out about all that the alcohol dissolves. As a rule, the free alkaloids are much more soluble in ether or chloroform than are their salts, but morphine is an exception. Morphine dissolves in 300 parts of alcohol (not enough in the two ounces of the tincture to dissolve the amount that would correspond to 15 grains of the sulphate), in 4000 parts of ether, or 6000 parts of chloroform. It is impossible to get the morphine sulphate or the free alkaloid into solution. The prescription should not be dispensed. 209. In neutralizing tincture of ferric chloride by adding am- monia water to it a precipitate is formed, consisting of ferric hydrate and basic ferric chloride. If the ammonia water is added to a part of the syrup, and then this added to the tinc- ture of iron previously diluted with the balance of the syrup, no precipitation will occur even though an excess of ammonia is used. The resulting fluid is of a very dark red color. The syrup acts as a solvent for the ferric hydrate. It is better to add a strong solution of ammonia than a weak one, as the water dilutes the syrup so much that it may not prevent the precipitation. 228 INCOMPATIBILITIES IN PRESCRIPTIONS. 210. This makes at first a clear colorless solution, but within a day or two becomes of a dark brownish-red color. On standing a few days there is a slight precipitation, the amount depending on the condition of the salt and the spirit. If the salt is neutral and the spirit strongly acid a small amount of salicylic acid will be thrown out of solution. By neutralizing the acid the precipitation is prevented and the coloration hindered, although care must be used not to make the solution alkaline, as an alkaline solution of a salicylate •quite quickly becomes colored. Possibly there is some nitrosalicylic acid formed in this prescription. The directions are: Mix. Label: Dessertspoonful three times a day. 211. On adding the sulphurous acid to the tincture of iron the mixture becomes of a much darker red color at first and then nearly colorless. The glycerin may now be added and then the potassium chlorate dissolved in the water. There is barely a sufficient amount of water to dissolve the chlorate at the ordinary temperature, and after mixing with the other ingredients some of the salt is thrown out of solution by the ■alcohol of the tincture. Different chemical reactions take place, depending on the order of mixing. The possible reactions are as follows: i. Between the ferric iron and the sulphurous acid, forming ferrous sulphate and hydrochloric acid. 2. Between the potassium chlorate and the hydro- chloric acid in the tincture, forming chlorine. 3. Between the chlorine and the ferrous sulphate, forming a ferric salt and a chloride. 4. Between the chlorine and the sulphurous acid, forming sulphuric and .hydrochloric acids. 5. Between the chlorine and the glycerin. 6. Between the potassium chlor- ate and the sulphurous acid, forming potassium sulphate and hydrochloric acid. INCOMPATIBILITIES IN PRESCRIPTIONS. 229 212. This prescription was filled by dissolving the inorganic salts in the water and the camphor in the alcohol. The tinc- ture was added to the alcoholic solution and then the two solutions mixed. A turbidity resulted at once, and on stand- ing for some time crystals were formed. This is due to the insolubility of the inorganic salts in the alcohol, which throws them out of their aqueous solution. 213. There is barely enough of water to dissolve the borax, it being soluble in 16 parts of water. Mercuric chloride requires about 16 parts of water, and the twenty grains would require about two thirds of an ounce. If the mercuric chloride is ■dissolved in part of the water, and the borax is mixed with the balance of the water and then with the corrosive sub- limate solution, or if the borax is dissolved in the water and then the mercuric chloride added to this, the result will be about the same. In either case there will be formed a dark reddish-brown precipitate of an oxychloride of mercury, and also a white precipitate of borax or boric acid. The mercury is ultimately entirely precipitated. If heat is used in dissolv- ing the borax there are quite large clear crystals formed on standing, probably borax. The directions are: Make a lotion. Use frequently. 214. The carbonate in the Fowler's solution precipitates the ferrous carbonate, which is white if purely ferrous, but quickly oxidizes, changing to a dark green. This slowly oxidizes still more, forming a red-brown basic ferric salt. Probably some of the arsenic is also precipitated. The sugar in the syrup tends to prevent the oxidation of the ferrous carbonate. 230 INCOMPATIBILITIES IN PRESCRIPTIONS. 215. Piperazin is so deliquescent that it becomes liquefied when exposed to air; consequently it cannot well be dispensed in the form of powders. Probably the best way is to put it into good capsules, and even then it may liquefy. It also absorbs carbon dioxide from the air. The directions are: Let it be triturated well. Let 12 powders be made. 216. The cocaine hydrochloride is best dissolved in a little water before mixing with the base. No difficulty is experi- enced in filling this prescription, but the use of a metallic spatula must be avoided. 217. Crystallized carbolic acid when triturated with lead acetate or with thymol gives a liquid, and the reaction cannot be prevented by first mixing the ingredients with separate por- tions of the base and then rubbing these together. The mass is too soft to make into suppositories, and it is necessary to use some drying-powder or spermaceti to stiffen it. The directions are: Mix carefully. Make 10 suppositories. 218. Three chemical reactions may take place in mixing these ingredients. One is between the sodium benzoate and the sulphuric acid, forming sodium sulphate and benzoic acid. The benzoic acid is only sparingly soluble in water, but there is enough of alcohol in the elixir to keep it in solution. Another reaction is between the sulphuric acid and the quinine sulphate, making the soluble bisulphate. The third reaction is between the sodium benzoate and the quinine salt, forming quinine benzoate, which is not very soluble in water. The prescription was filled by dissolving the quinine sulphate INCOMPATIBILITIES IN PRESCRIPTIONS. 231 in part of the elixir and the benzoate in the remainder and then mixing the solutions. Precipitation commenced almost at once and in a short time there was a solid mass of needle- shaped crystals. This could be shaken up so that it could be poured. 219. The quinine sulphate was dissolved in the tincture of iron with the hydrobromic acid and then an aqueous solution of the corrosive sublimate added. A precipitation commenced at once and continued for some time. Mercuric chloride is a general alkaloidal reagent, and so also is the double com- pound that it forms with the hydrobromic acid; these combine with the quinine to form insoluble compounds. In such a prescription as this the danger lies, not in the precipitation of the quinine, but of the mercuric chloride, and in this par- ticular instance it is almost entirely thrown out of solution. This prescription might be considered dangerous to dis- pense. 220. The potassium nitrate and the lead acetate were powdered separately and then mixed with the oil. To this the sul- phuric acid was added slowly with constant stirring, avoiding letting the mixture get hot. The carbolic acid was added last. The mixture thus produced was black and thick. Several reactions ensue, depending to some extent upon the order of mixing, i. Sulphuric acid with lead acetate gives lead sulphate and acetic acid. 2. Sulphuric acid with potas- sium nitrate forms potassium sulphate and nitric acid. 3. The nitric acid may act on the oil, oxidizing it. 4. The nitric acid may act upon the carbolic acid, forming picric acid. 5. The sulphuric acid forms with carbolic acid sulpho- carbolic acid. 6. Sulphuric acid has a carbonizing effect upon the oil. 232 INCOMPATIBILITIES IN PRESCRIPTIONS. 221. No matter what order is used in mixing these ingredients a clear solution cannot be obtained. Several chemical reac- tions are liable to take place. i. Potassium acetate with tincture chloride of iron gives a red solution of ferric acetate. 2. Potassium acetate with a solution of quinine sulphate gives the almost insoluble quinine acetate. 3. Sodium bicarbonate precipitates morphine from a solution of its salt. 4. Sodium bicarbonate precipitates ferric hydrate from the tincture of iron. 5. Sodium bicarbonate precipitates the quinine from a solution of the sulphate. 6. The morphine sulphate gives a blue-green solution with the tincture of iron. By replacing one half of the water with glycerin the precipi- tation can be prevented to some extent. 222. The strychnine and the iodoform are insoluble in the syrups. The strychnine sulphate should be used instead of the alkaloid and then it will dissolve in the syrups. The iodoform should be finely powdered before mixing with the other ingredients and a " Shake " label should be put on the bottle. Very frequently syrup of hydriodic acid contains some free iodine, which would precipitate the alkaloids, but by mixing the two syrups first the iodine is reduced by the hypophosphorous acid in the syrup of hypophosphites. There is perhaps a little danger of the hydriodic acid precipi- tating the strychnine, as under certain conditions iodides pre- cipitate that alkaloid. 223. On adding a part of the glycerin to the balsam a nearly solid mass results which is thinned some by the balance of the glycerin so that it will run slowly. There may be some chemical reaction, but more probably the thickening is due to the separation of part of the resinous matter. On standing INCOMPATIBILITIES IN PRESCRIPTIONS. 235 exposed to the air the glycerin absorbs moisture and the mixture becomes thinner, the balsam coming to the top. The odor of the iodoform is destroyed, the balsam combining with the iodoform (U. S. D., 741). 224. The vaselin will not dissolve in the bay rum and on being melted and shaken with the bay rum until cold separates in a mass. Acacia cannot be used to emulsify it on account of the alcohol present. The addition of soap or resinous matter in admissible amounts does not help it. If lanolin is used in- stead of petrolatum the acid can be mixed with it and about one half of the alcohol, making a homogeneous mass, but the balance of the alcohol separates. The amount of carbolic acid is very large, the mixture being so strong as to quickly make the skin white. The prescriber should be consulted. 225. If the sodium salicylate is dissolved in a little water and then added directly to the tincture of iron ferric salicylate is precipitated. This can be prevented by diluting the iron with the solution of ammonium acetate. The oil of winter- green does not dissolve in the glycerin or the mixture of other ingredients. The solution is colored deep red by the ferric salicylate. If the tincture of iron and the solution of ammonium acetate are quite strongly acid there may be a precipitate of salicylic acid. 226. Exalgin triturated with camphor makes a damp powder, or with salol it gives a liquid. Salol and camphor triturated together give a liquid. This mixture cannot be dispensed in the form of powders unless a large amount of some absorb- ing-powder, as slippery elm, is used. Perhaps the best way to dispense this combination would be to get the prescriber's: ^34 INCOMPATIBILITIES IN PRESCRIPTIONS. consent to make an emulsion with water and acacia, using' •some expressed oil of almond to aid the emulsification. 227. The mercuric chloride with potassium iodide gives the potassium mercuric iodide (Mayer's reagent) which precipi- tates nearly all alkaloids, quinine not being an exception. The precipitation is prevented to considerable extent by the presence of alcohol, but there is not a sufficient amount here. In filling this prescription Mr. ]Martindale advises the use of one and a half ounces of glycerin in place of a like amount of water, when no precipitation occurs. His directions are to rub the quinine with the glycerin, then add the iodide, the tincture, the spirit, and lastly the mercuric chloride dissolved in water. 228. On mixing these two ingredients a white precipitate of calcium carbonate is formed, the spirit containing ammo- nium carbonate. The lime water also throws out of solution the oils of the aromatic spirit. Ordinarily the precipitate would not be filtered out but the mixture dispensed with a " Shake well " label. 229. The bismuth subnitrate is not dissolved. The aromatic spirit of ammonia precipitates the zinc as zinc carbonate, due to the presence of ammonium carbonate. The carbonate may be slowly decomposed by the bismuth subnitrate, liberat- ing carbon dioxide, which might burst the bottle if tightly corked. Tragacanth is perhaps as good as anything for sus- pending bismuth subnitrate. A " Shake well " label is neces- sary. INCOMPATIBILITIES IN PRESCRIPTIONS. 235 230. Ergotin does not mix well with alcohol and should be rubbed up with a little water first and then triturated thor- oughly with the tincture. The mixture is not clear at best. 231. Reaction takes place between the two chemicals, resulting in the formation of the soluble ammonium acetate and the precipitation of a white basic carbonate of lead, which is really a carbonate and hydrate combined in various proportions. All the lead is precipitated. As it is for external use, it may be dispensed. 232. This prescription would make pills weighing nearly eight ■grains each even though no excipient is used, and as two of the ingredients are liquids, it would require a large amount of an absorbent powder to make a mass and the pills would be entirely too large. A smaller amount of excipient can be used, and at the same time a larger amount of medicinal matter can be taken, in the form of capsules than in a pill. This prescription should either be put into capsules or be made into two or three times as many pills as directed, of course increasing the number to be taken at a dose. 233. Several chemical reactions take place, depending on the order of mixing. The quinine sulphate is not all dissolved by the elixir. i. The sodium salicylate combines with the- quinine salt, forming the nearly insoluble quinine salicylate. 2. The quinine sulphate forms with the mercuric chloride a double compound which is insoluble in water but soluble in alcohol. In this particular instance there is not enough of alcohol in the elixir to dissolve it. 3. The quinine is also 236 INCOMPATIBILITIES IN PRESCRIPTIONS. precipitated as the free alkaloid by the alkali in Fowler's solution. 4. An alkaline solution of potassium arsenite re- duces mercuric chloride to calomel, but in this prescription there is not enough to make any trouble. In filling this,, quite a bulky precipitate results, but by increasing the alcohol so that it will be about fifty per cent, there will be little or no precipitation. 234. The U. S. Dispensatory (17th ed., 716) gives a formula for making the colorless hydrastis, which consists of twenty grains of hydrastine hydrochloride or sulphate dissolved in a. pint of a mixture of glycerin and water. In this prescription w^e have the borax decomposed by either the honey or the glycerin, forming boric acid and sodium metaborate. The boric acid liberates carbon dioxide from the sodium bicar- bonate. Carbon dioxide may also be liberated by the bis- muth subnitrate, bismuth subcarbonate being slowly formed. The bicarbonate of sodium may also liberate the hydrastine from the acid with which it is combined, but the alkaloid will not be precipitated in the presence of so much honey, glyc- erin, and water. 235. The compound liniment of camphor contains ammonia,, and this w-ith the iodine forms ammonium iodide and a little ammonium iodate. The mixture at first is red-brown, but becomes colorless as the iodine is changed. There is some danger of forming the explosive iodide of nitrogen. [See under Iodum.] 236. This mixture quickly becomes blue, the color gradually deepening, and a turbidity is produced. The addition of an acid turns it red. Mention is made of this change in Allen's INCOMPATIBILITIES IN PRESCRIPTIONS. nr Organic Analysis (vol. ii. p. 539), and also in Muir and Mor- ley's edition of Watts' Dictionary (vol. iii. p. 832), but no explanation is given nor intimation of the chemical change which takes place. 237. The trouble in filling this prescription comes in getting the extracts into solution. The best way is to make a very strong aqueous solution of the chloral hydrate and this will dissolve the extracts; to this solution add the alcohol and then the water containing the bromide, the latter solution to be added slowly with constant stirring. Some precipitate will form but it can be readily diffused through the liquid by agi- tation. Using another ounce of alcohol makes a better solu- tion. 238. In Scoville's Art of Compounding the statement is made that sodium bicarbonate with calomel forms corrosive sub- limate slowly, the change not taking place within four to six weeks ordinarily, so that, except under unusual conditions, any prescription would be used before mercuric chloride is formed. It is a very common practice of physicians to direct the use of these two chemicals together and no ill effect seems to have resulted. 239. Sodium bicarbonate requires 11.3 parts of water for solu- tion. While there is suf^cient water to dissolve the two salts and the acid, a precipitate very slowly forms after the addi- tion of the chloroform, due, probably, to the throwing out of solution some of the bicarbonate by the chloroform. The chloroform is not all dissolved, but sinks to the bottom. In dissolving sodium bicarbonate in water heat should not be used, because carbon dioxide is liberated, forming the normal 238 INCOMPATIBILITIES IN PRESCRIPTIONS. sodium carbonate. Carbolic acid does not liberate carbon dioxide from the sodium bicarbonate. 240. When antipyrin is rubbed with resorcin a pasty mass re- sults, and this gradually becomes liquid. Acetanilid and resorcin triturated together make a liquid. When an aqueous solution of antipyrin is mixed with a solution of resorcin a white precipitate is formed. Acetanilid requires 194 parts K)i water for solution, so that in this prescription it will not be all dissolved. No matter how this is filled a clear solu- tion cannot be made without the addition of alcohol or some other solvent. 241. Cocaine hydrochloride is soluble in 2800 parts of ether or 3.5 parts of alcohol. As collodion is made up of 3 volumes of ether to i of alcohol, this salt will not dissolve in it. The free alkaloid cocaine is readily soluble in alcohol or ether, and consequently in collodion. The free alkaloid should be used and the prescriber notified of the change. 242. Atropine sulphate is nearly insoluble in fixed oils. The free alkaloid is soluble in 38 parts of olive oil, and this is what should be used in filling this prescription. The physician should be notified of the change." 243. The chromic acid and cocaine hydrochloride were dis- solved in separate portions of water, using one dram for each, and these solutions were mixed. A heavy yellow sticky pre- cipitate formed which made a mass. It is necessary to use about twelve drams of water to get a clear solution and then it may precipitate on standing for a time. Alcohol or glycerin INCOMPATIBILITIES IN PRESCRIPTIONS. 239 cannot be used with chromic acid. It cannot well be dis- pensed as written. 244. The spirit of nitrous ether gives a blue color with a fresh tincture of guaiac but a brown one with a tincture that has been exposed to the light for a time. The nitrous acid would probably affect the alkaloid colchicine, since it is so easily decomposed. Acids usually give yellow solutions with col- chicine, but this change would not be noticed here. The syrup precipitates resinous matter from the tinctures. 245. The potassium sulphide in the " liver of sulphur " pre- cipitates part of the zinc as the white zinc sulphide. There is left in solution some zinc sulphate, potassium sulphate,. and potassium thiosulphate. 246. The aromatic sulphuric acid was probably added to reduce the bulk of the quinine, but an incompatibility is thereby introduced. The acid will liberate the carbon dioxide from the mass of carbonate of iron, causing the pills to swell and forming ferrous sulphate. The acid should be omitted. 247. There will be a little silver permanganate thrown out of solution, it being soluble in 109 parts of water. This salt, like other silver salts, is decomposed by Hght and also by heat. 248. Thymol and menthol liquefy when triturated together. If a powder were used to mass the liquid the required cap- 240 INCOMPATIBILITIES IN PRESCRIPTIONS. sule would be entirely too large to swallow. By putting in the menthol, then the guaiacol carbonate, then the thymol, and lastly the eucalyptol, a kind of mass will be formed, but it will be necessary to seal the capsules. Or a drying powder can be used and the number of capsules and the dose be in- creased. 249. Benzoic acid is soluble in 500 parts of water and salicylic acid in 450 parts of water. If the directions to make a solu- tion with the aid of heat are followed the acids on cooling will separate out in much larger crystals than at first. A better mixture will be obtained by rubbing the acids well in the mortar and then mixing with the water and cocaine salt in the cold. The acids do not precipitate the alkaloid. 250. The analysis of antikamnia shows it to contain some sodium bicarbonate, which would react with each of the other ingredients of the prescription if a mass were made of them. The capsules would necessarily be too large even though the ingredients were made into a mass. The dose of strychnine is too large; the usual maximum limit is ^/2o of a grain, al- though some authorities give it as high as V12 grain. The prescriber should be consulted. 251. The oil, chloroform, spirit of camphor, and aromatic spirit of ammonia mixed make a clear solution, but on the addi- tion of the tincture and the whiskey the oil and chloroform are thrown out of the solution, and on standing the mixture separates into two clear layers the lower one being chloro- form and oil. There is no danger of the morphine being pre- cipitated, for, although the free alkaloid is formed by the ammonia, there is enough of alcohol and chloroform to keep it in solution. INCOMPATIBILITIES IN PRESCRIPTIONS. 241 252. The carbonate in the solution of potassium arsenite pre- cipitates the yellow-white silver carbonate. The arsenic also combines with the silver, forming yellow silver arsenite, which is insoluble in a neutral aqueous liquid. In this prescription the silver is not all precipitated. The yellow-white precipi- tate becomes dark on standing for a day, with the formation of silver oxide or metallic silver or both. 253. In the presence of moisture the potassium iodide reacts with the mercurous iodide, forming metallic mercury and the more active mercuric iodide. The potassium chlorate in the presence of a mineral acid, as the hydrochloric acid of the gastric juice, causes the liberation of iodine. It should not be dispensed as written. 254. Castor oil and nearly all other fixed oils do not make clear solutions with glycerin. A " Shake well " label is necessary for this prescription. The oil need not be emulsified, as the two liquids are thick and do not separate quickly. 255. The ammonia and the oil in the liniment reduce the iodine to an iodide, the fresher the liniment and the more ammonia present, the larger the proportion of iodine reduced. The oily matter is rather heavier than the alcohol and it forms a globule in the bottom of the mixture. The two liquids can \)t readily mixed by agitation. 256. The two ingredients cannot be mixed so as to make a homogeneous mass as the alcohol does not mix with fatty 2^2 INCOMPATIBILITIES IN PRESCRIPTIONS. matter. The iodine combines with the mercury to form mer- curous iodide and then mercuric iodide. In a day or two the liquid becomes nearly colorless. There is no way to remed}^ the trouble except by rewriting the prescription. 257. The antipyrin was dissolved in the syrup and added to the syrup of iodide of iron without producing any apparent change at first. After a day or two, however, the liquid be- came dark red and a crystalline precipitate of a deep-red color began to form. These crystals grew as the liquid was allowed to stand. Their composition was undetermined. 258. Potassium permanganate oxidizes carbolic acid to oxalic acid and carbon dioxide. (Morley and Muir, iii. 832.) The permanganate is reduced and precipitated as man- ganese dioxide, which makes the mixture a semi-solid, but by shaking it may be gotten into a condition so that it can be poured. There is a large excess of carbolic acid not oxidized. 259. If a solution of borax is added to a solution of lead acetate a white precipitate of lead borate is formed. Or if the glycerin is added to the solution of lead acetate and then the borax solution added a precipitate is also formed. But if the glycerin is added to the borax solution first the borax is decomposed, with the ultimate formation of sodium meta- borate and boric acid, making an acid solution which does not precipitate the lead. 260. The iodine is reduced by the tannic acid, but not com- pletely, and a turbid mixture is made. According to the U. S. INCOMPATIBILITIES IN PRESCRIPTIONS. 243: Dispensatory (p. loi), hydriodic acid is formed and combines with a portion of the tannic acid and remains in solution, while the oxygen of the decomposed water combines with another portion of the tannic acid to form an insoluble com- pound. This mixture is capable of dissolving iodine. 261. If the potassium chlorate and the glycerin are rubbed together an explosion is liable to occur. The chlorate and acid react to form a chloride and sulphate. After a day or two no odor of sulphurous acid can be detected. The chlorate does not all dissolve in the water, but the excess should not be filtered out, as it is to be mixed with more water before being used. 262. Chromic acid oxidizes glycerin to oxalic and carbonic acids; it oxidizes alcohol to aldehyde and acetic acid. There is great danger of causing an explosion or igniting the organic matter in filling this prescription. The reaction is. very violent. The chromic acid is changed to an insoluble oxide of chromium. 263. The National Dispensatory (p. 847) states that when the first two ingredients are rubbed together explosion takes place, due to the formation of iodide of nitrogen. By mixing the first two ingredients with separate portions of lard and then mixing these there is but little danger. The iodine is reduced and the ointment becomes nearly white. 264. When the salol is added to the tincture of iron a dark- green to red mixture is produced. The salol is partially dis- solved., but is nearly all precipitated when the syrup is added^ 244 INCOMPATIBILITIES IN PRESCRIPTIONS. According to the U. S. Pharmacopoeia, with a dilute solution of iron an alcoholic solution of salol gives a violet color, while a dilute solution of salol added to the iron solution gives a whitish turbidity. 265. The tincture of iodine and the collodion mix without any- trouble or any reduction of the iodine even on standing for several days. But when the ammonia water is added and thoroughly shaken with the mixture it coagulates the collo- giving a dark-red solution. The syrup of ginger was next added and lastly the ammoniated tincture of guaiac, the first few drops of which gave a green color, that had changed to blue by the time all of the tincture was added. On standing a few minutes it had changed back to a blue-green, and then green, and in a few hours to a dark brown. Guaiac with ferric chloride or other oxidizing agent gives a blue color. The resinous matter of the guaiac and also the oils of the aromatic spirit of ammonia (the menstruum used in making the tinc- ture) were precipitated by the syrup. The ammonia and ammonium carbonate precipitate the quinine and also the iron; the ferric hydrate is somewhat soluble in syrup, but in this case the syrup is too much diluted by the tinctures to INCOMPATIBILITIES IN PRESCRIPTIONS. 249 keep all of the iron in solution. The precipitated matter is bulky and rather gelatinous, but the mixture can be dispensed with a " Shake well " label. 283. Potassium permanganate oxidizes quinine sulphate to pyridin tricarboxylic acid, oxalic acid, and ammonia (M. & M., IV. 375). It also oxidizes the iron. When the per- manganate and the iron are rubbed together a detonation takes place. The excipient should be one that will not reduce the permanganate, and it should also protect the other in- gredients; a mixture of equal parts of paraffin, petrolatum, and kaolin is a good one, or resin cerate with althea may be used. 284. The strychnine will not dissolve in the glycerin or in the water. The consent of the prescriber to use strychnine sulphate or nitrate (the nitrate is the more common for hypodermic injection) should be obtained. In the absence of the prescriber the nitrate should be dispensed, notifying the prescriber of the change at the earliest possible opportunity. 285. Carbolic acid and thymol when triturated together form a liquid which can be mixed with the vaselin and cerate, mak- ing a homogeneous mass. On allowing it to stand for a time the liquid separates to some extent, though hardly enough to do any harm. This can be prevented by using lanolin in- stead of petrolatum. Using one half dram of lanolin for that amount of vaselin does not entirely prevent the separation. 286. Sodium phosphate precipitates a solution of lithium bromide as lithium phosphate. There is more sodium phos- 250 INCOMPATIBILITIES IN PRESCRIPTIONS. phate than the water will dissolve. Heat should not be used to aid the solution, since on cooling large crystals will form. The phosphate should be powdered and the cold water al- lowed to dissolve what it will. Even then the part left un- dissolved may form a crystalline mass that can be gotten out of the bottJe only by heating. 287. Podophyllin gives a black-brown color with the tincture of iron and nearly all is dissolved on warming. Quinine sul- phate dissolves in this solution, and when the tincture of rhubarb is added the tannic acid in it precipitates the quinine, and with tincture of ferric chloride gives the black tannate of iron. The mixture is quite thick from the precipitated matter. 288. When camphor and carbolic acid are brought together a liquid results. In order to avoid making any more liquid than was necessary the corresponding amount of solid iodine was used in place of the tincture. The iodine dissolved readily in the phenol-camphor liquid and then the powdered lead acetate was added. Kaolin was tried as an absorbent excipient, but the amount required made the pills entirely too large. Starch was then used together with some glucose syrup, so as to form the easily decomposed iodide of starch. This made the pills very large and they were finally put into capsules. 289. This prescription made at first a clear pale-yellow solu- tion. Within about an hour crystals began to form and by the next morning there was quite a heavy deposit of nearly colorless prismatic crystals besides some smaller red-brown crvstals. In concentrated solutions potassium iodide pre- INCOMPATIBILITIES IN PRESCRIPTIONS. 251 'cipitates the quinine as a double iodide which is white. Citric acid liberates hydriodic acid and this is oxidized by the air forming iodine. The free iodine precipitates the quinine, giving red-brown crystals. 290. Phenacetin is only sparingly soluble in water, but more soluble in alcohol, although there is not enough present in this prescription to dissolve it entirely, and what is dissolved is again thrown out of solution on adding the water. Heating the phenacetin with the tincture causes solution to take place, giving a dark-red color. On adding water the color is de- stroyed and the phenacetin is precipitated. The best way to fill this prescription is to powder the phenacetin, mix with a little acacia, and add the water and lastly the tincture of iron. Filled in this way the phenacetin is in a finer powder than when it is first dissolved in the tincture. 291. The sodium salicylate and benzoate and the carbolic acid were dissolved in the lime water, making a nearly clear color- less solution, and then the tannic acid was added. A blue- white precipitate was formed, due to the reaction between the tannic acid and lime water. The precipitate afterwards slowly turned to a dirty-yellow color. 292. This gave a clear solution at first but a turbidity was noticed within an hour and by the next morning the bottom of the bottle was covered with a white precipitate which re- sponded to the tests for calomel. Mercuric chloride is slowly reduced to calomel by alcohol (M. & M., i. 98). This does not explain the ready reduction that occurs, and the writer is inclined to think that the nitrous ether or acid has some effect, notwithstanding the fact that some writers say that 252 INCOMPATIBILITIES IN PRESCRIPTIONS. nitrous acid does not reduce mercuric salts. (See P. & J.^ 203.) 293. The solution of morphine contains some free hydrochloric acid, which reacts with the potassium chlorate, with the for- mation of a very small amount of chlorine. The chlorine oxi- dizes a portion of the morphine, giving a pale-brown solution. By dissolving the chlorate in the water and diluting the solu- tion of the morphine with the syrup and then mixing, scarcely any coloration is produced, and none when the free acid is neutralized. 294. The mercuric chloride reacts with the hydriodic acid^ forming the red iodide of mercury, and then this combines with more hydriodic acid to form a soluble double compound which precipitates the cinchona alkaloids. Extractive matter in the fluid extract is also precipitated by the water in the syrups and solution. There is such a small amount of mer- cury precipitated that the mixture is not a dangerous one.. It should be dispensed with a " Shake well " label. 295. Adding the tincture to the syrup produces a gelatinous precipitate which dissolves on adding the acid. The precipi- tate is ferric hypophosphite which is decomposed by the phos- phoric acid forming ferric phosphate which is soluble in excess of acid. If the prescriber had used hydrochloric acid instead of the phosphoric the precipitate would have not dis- solved, the iron having a stronger affinity for the hypophos- phorous acid than for hydrochloric but less than for the phosphoric. INCOMPATIBILITIES IN PRESCRIPTIONS. 253 296. The syrup of iodide of iron frequently contains some free iodine, which would precipitate the quinine. By warming the two syrups the iodine is reduced by the hypophosphorous acid in the syrup of hypophosphites. When quinine sulphate dis- solved in the phosphoric acid is added to the mixed syrups a white amorphous precipitate is formed which is probably calcium sulphate. Some of the quinine is also precipitated on allowing the mixture to stand. 297. By dissolving the morphine in a little water and adding it to the tincture of iron a blue solution is formed which quickly turns green. When the calcium hypophosphite, dissolved in the water and syrup, is added a white precipitate of ferric hypophosphite is thrown down. The color of the solution is nearly but not entirely destroyed. By adding the morphine dissolved in water to the mixture of other ingredients no coloration is produced, and this is the method that should be followed, as the morphine is not decomposed by the iron hypophosphite. The precipitate of ferric hypophosphite can be dissolved by adding some potassium citrate to the moist magma. A better method of filling is to use the tincture citro- chloride of iron of the National Formulary instead of the official tincture of iron, the two tinctures having the same iron strength. By using it no precipitation takes place for several days at least. 298. The doses of the first two ingredients are too large. The rrraximum dose of mercuric chloride is about Ve of a grain and of sodium arsenate about ^/g of a grain. The prescription should not be dispensed without first consulting the pre- scriber. Should it be filled the potassium carbonate will react 254 INCOMPATIBILITIES IN PRESCRIPTIONS. with the strychnine, the mercury, and the iron salts, but the activity is not increased. 299. The soap acts as an emulsifying and solidifying agent and the consistency of this mixture is about that of lard. Soap is nearly always alkaline and acts on the calomel, producing the black mercurous oxide. This explains why the mixture slowly turns dark. 300. This prescription was filled by dissolving the quinine sul- phate in a portion of the water with the aid of the acid; the potassium iodide dissolved in the balance of the water was added and lastly the sodium arsenate solution. The solution was clear and of a pale-yellow color. Within five minutes precipitation had commenced, and in less than fifteen minutes there was quite a heavy purple-red precipitate. Within a few hours a solid mass had formed which was of a purple- chocolate color. Sodium arsenate in the presence of an in- organic acid oxidizes potassium iodide, liberating iodine, and this precipitates the quinine. 301. If the directions to use enough of the extract of gly- cyrrhiza to make a pill-mass be followed, the pills will be en- tirely too large. The best way is to melt one gram of beeswax, add the balsam and stir till the mixture is cool. Then use enough of powdered liquorice root to make the mass. Some would prefer to make twice the number of pills and double the dose. 302. It is impossible for the dispenser to tell what the pre- scriber wanted. " Hvd." mav stand for hvdrochloric, hvdro- INCOMPATIBILITIES IN PRESCRIPTIONS. 255 bromic, hydriodic, or hydrocyanic. From the directions to the patient to take after meals probably hydrochloric was what was intended, but it would be necessary to consult the physician. 303. By rubbing the powdered tragacanth with the petrolatum, then adding the glycerin and zinc oxide, a comparatively smooth ointment can be made, but the glycerin separates on standing. The glycerin and tragacanth should be heated together, with the addition of a little water if necessary, so as to make a glycerite of tragacanth, and then mixing this with the other ingredients a smooth permanent ointment can be made. 304. Potassium iodide is deliquescent in moist air, and on pow- dering, even in the ordinary atmosphere, it becomes damp. It may be necessary to add some absorbing-powder. The powders should be dispensed in paraffin or wax paper. 305. In making ointments the medicinal ingredients must be in the form of a fine powder, soft solid, or solution. Iodine is powdered with difficulty. It might be dissolved in alcohol and this solution added to the lard. The U. S. Pharma- copoeia directs that it be dissolved in an aqueous solution of potassium iodide, using one fourth as much potassium iodide as iodine and twice as much water as iodide. Lard will hold nearly 10 per cent, of its weight of water. 306. This was filled by dissolving the quinine in a little water with the aid of the acid, adding the syrup, and lastly the potassium chlorate dissolved in the water. The solution was. 256 INCOMPATIBILITIES IN PRESCRIPTIONS. clear and nearly colorless at first, but in a few minutes a red- brown precipitate began to form and increased until the mix- ture was quite thick. Sulphuric acid liberates chloric acid from the potassium chlorate, and this oxidizes the ferrous iodide, liberating iodine, which precipitates the quinine. 307. Phenacetin requires 1400 parts of water or 6 parts of alco- "hol for solution. In filling this prescription the phenacetin can be dissolved in the tincture and spirit, but on adding the syrup and water nearly all of it will be thrown out of solu- tion. A better mixture would be made by powdering the phenacetin with about two drams of acacia, then adding the syrup and part of the water, and lastly the tincture and spirit ■diluted with the balance of the water. 308. An absorbent excipient is necessary in order to make a pill-mass. To use a powder like liquorice root or althea would make the pills too large. Freshly calcined magnesia dampened with a little water is the best, as it is only necessary to use six or eight grains. The magnesia combines with the copaibic acid in the balsam to form a solid mass; a little water aids the reaction and it may be necessary to use the heat of a water-bath. A little drying powder will still be required. 309. With bismuth subnitrate salicylic acid forms a series of nitrosalicylates of bismuth, varying in color from a white to a reddish orange. This mixture gives a faint pink color after standing for a time. 310. Chloral hydrate rubbed with phenacetin gives a liquid, a sticky mass is also obtained when chloral hydrate is rubbed INCOMPATIBILITIES IN PRESCRIPTIONS. 257 ■with quinine sulphate. A large amount of an absorbent pow- der would be necessary to make this liquid into a mass, and the capsules would necessarily be very large. 311. The alcohol in the tincture is without any therapeutical value in this case, and only makes the pill-mass too soft. The ■alcohol should be evaporated before mixing with the other ingredients unless the extract of jalap has become dry and hard, in which case it can be used to soften the extract and then evaporated. 312. Twenty grains of salicylic acid require nearly nineteen fluid ounces of water for solution, but in this case the acid combines with the calcium hydrate to form a soluble calcium salicylate. The solution is clear and slightly acid. 313. When the acetanilid is added directly to the tincture of iron and heated it makes a deep-red clear solution. On adding the water the acetanilid is precipitated and the color changed back to that of diluted tincture of iron. A better mixture can be made by powdering the acetanilid first, mixing with water and acacia or tragacanth, then adding the tincture of iron highly diluted with water. The tincture of iron, unless diluted with water, has a tendency to coagulate acacia. [See ACETANILIDUM, No. 2.] 314. The hydrogen dioxide oxidizes the ferrous iron to a ferric salt and the glycerin to glyceric, oxalic, and tartaric acids, and in an acid solution reduces the bichromate to a green chromic salt. The hydrogen dioxide usually contains some sulphuric acid, which is left in to preserve it. In the presence 258 INCOMPATIBILITIES IN PRESCRIPTIONS. of free acid the bichromate oxidizes the ferrous sulphate and the glycerin. This prescription gives a heavy brown precipi- tate, probably of a basic ferric salt. 315. So long as this mixture is kept from the light it does not change in color, but on exposure to direct sunlight for a few hours, or to diffused light for a longer period, it acquires a red color. This is due to the decomposition of iodoform, liberating iodine, and the iodine combines with and oxidizes the calomel, forming mercuric iodide. 316. The trouble with this prescription is that the water breaks up the boroglycerin, liberating boric acid. Boric acid requires about 25 parts of water for solution, and there is not enough to dissolve it. By replacing one half of the water with glyc- erin no precipitation results. 317. The salicylic acid is not soluble in the water and glycerin; it requires 450 parts of water for solution, and, according to the U. S. D. (p. 84), by careful heating it will dissolve in 50 parts of glycerin. If the acid is dissolved in the glycerin with the aid of heat and ihe tincture then added a clear solu- tion results, but on adding the water a bulky crystalline pre- cipitate comes down. A better method of filling is to rub the acid with the glycerin and water and then add the tincture. Free iodine reacts with salicylic acid, giving mono-, di-, and tri-iodobenzoic acids and tri-iodophenol (M. & M., iii. 680). All of the iodine is not changed. 318. The citrate of iron and quinine was dissolved in a part of the wine, making a clear acid solution. To this was added INCOMPATIBILITIES IN PRESCRIPTIONS. 259 the carbolic acid dissolved in the balance of the wine. A light-yellow sticky precipitate was formed. The composition of the precipitate was not determined, but on testing it quinine was proved to be present. Moreover, when iron citrate is used instead of the iron and quinine citrate no pre- cipitation occurs. The precipitate is not dissolved by the further addition of the tincture, neither is precipitation pre- vented by adding a little dilute sulphuric acid. The tinc- ture darkens the mixture a little and slightly increases the turbidity. 319. Diuretin is sodium-theobromine salicylate and is readily soluble in water. Acids decompose it, with the precipitation of the theobromine. Theobromine differs from many alka- loids in that it does not readily combine with acids. In this prescription the diuretin was dissolved in the syrup, and then the spirit of nitrous ether added, and lastly the tincture of iron. When the iron is added a very deep violet color is produced, due to the formation of ferric salicylate, and on allowing the mixture to stand a few hours a white precipitate falls; the acids in the tincture and spirit liberate the theobromine. 320. Quinine sulphate makes a sticky mass when rubbed with the chloral hydrate; the antipyrin and the chloral form a mass on being triturated together. Even if the ingredients a:e powdered separately and mixed lightly, the mixture becomes sticky. By the use of a Httle drying-powder it can be put into capsules. 321. The pilocarpine differs from many alkaloids in that it is soluble in water. The hydrochloride is used much more fre- 26o INCOMPATIBILITIES IN PRESCRIPTIONS. quently than the free alkaloid. The terpin hydrate requires about 250 parts of water for solution; consequently only a small portion of it will be dissolved. A '* Shake " label is necessary. A more elegant preparation would be made by •emulsifying it. 322. The potassium bicarbonate precipitates the ferr6us iodide as ferrous carbonate. If the iron salt is purely ferrous the carbonate will be white, but it oxidizes in the air, becoming green and after some time yellow-brown, forming a ferric oxide. A little cai'bon dioxide is given off. In the alkaline mixture the iron does not oxidize the iodide. 323. An absorbent powder will be necessary to make a mass that can be put into capsules. When pyrocatechin is rubbed with acetanilid or phenacetin a liquid results. Acetanilid and phenacetin do not liquefy. 324. This combination has perhaps caused more trouble than almost any other one prescription. The U. S. P. phosphate of iron may be a double compound of sodio-ferric citro-phos- phate or it may be a mixture of ferric phosphate and sodium citrate. If it is the double compound (and there are reasons for thinking that it is) the phosphoric acid decomposes it, pre- cipitating the phosphate of iron. If it is a mixture the ex- planation given is that the sodium citrate is readily soluble in water and an aqueous solution of it is a good solvent for the ferric phosphate. Now when phosphoric acid is added it is supposed that the sodium citrate is decomposed, form- ing sodium phosphate and citric acid; the ferric phosphate, being no longer soluble in this solution, is precipitated. This difficulty can be overcome by using strictly pure dilute INCOMPATIBILITIES IN PRESCRIPTIONS. 261 inetaphosphoric acid (known also as glacial phosphoric acid) in place of the official orthophosphoric acid. A solution of metaphosphoric acid changes in time, forming some ortho- phosphoric acid, and if the meta-acid contain some of the ortho-variety a precipitation will occur. The dispenser must decide for himself as to the substitution proposed. There is sometimes, however, another difficulty present in this com- bination of ingredients. When quinine sulphate is present in a much larger proportion than two grains to the dram a pre- cipitation of the quinine by the ortho- or the meta-acid takes place, and there seems to be no way to make a permanent solution. There is always some objection to dispensing a *' Shake " mixture when it contains such an active agent as strychnine. 325. In a neutral solution potassium iodide does not react with the tartrate of iron and potassium, but in the presence of the sulphuric acid the ferric salt oxidizes the iodide, liberating iodine. This iodine then combines with the quinine to form an insoluble compound. A " Shake well " label is necessary. If there were much more free iodine than would combine with the quinine the prescription should not be dispensed. 326. The quinine sulphate was dissolved in the tincture of iron and a portion of the elixir added. The strychnine sulphate was dissolved in the balance of the elixir and added to the iron solution and the phosphoric acid added last. Adding the acid causes the formation of a nearly white precipitate which is phosphate of iron. If water is used in place of the elixir no precipitation results. The phosphate of iron is in- soluble in water but souble in acidulated water, and it is thrown out of solution by the alcohol in the elixir. 262 INCOMPATIBILITIES IN PRESCRIPTIONS. 327. This prescription was filled by rubbing the mercury with the iodine, then adding the glycerin, and lastly the tannic acid. Reaction takes place between the mercury and iodine, form- ing mercurous iodide and then mercuric iodide. Tannic acid reduces the iodine to hydriodic acid. Considerable red iodide of mercury is precipitated, although some is probably dissolved. This prescription is given in one of the standard works on therapeutics. 328. The arsenite in alkaline solution reduces the iodine to an iodide while the arsenite becomes an arsenate. About one eighth of the iodine is reduced. 329. This mixture if kept perfectly dry will not change in color, but pepsin is frequently hygroscopic and absorbs moisture in sufficient amount to enable a reaction to take place between the calomel and sodium bromide, causing the powder to turn black. Sodium bromide in the presence of moisture breaks up calomel, forming a mercuric compound and metallic mer- cury, the latter giving the dark color. Theoretically one half of the calomel goes to form mercuric chloride, and if this is really so there would be about one fourth of a grain of mer- curic chloride to the dose which would be dangerous. 330. Sodium bicarbonate is used in making the solution of saccharin, and while this solution makes a clear one with the strychnine at first yet on standing overnight the strychnine is precipitated. There is not enough of alcohol in the sac- charin solution to prevent it. The strychnine frequently ad- heres to the sides of the bottle, but may be loose, and in that case an overdose is liable to be taken. INCOMPATIBILITIES IN PRESCRIPTIONS. 263 331. The glycerite of boroglycerin which is called for can be mixed with the vaselin, but it separates on standing. Using lanolin in place of vaselin no separation occurs. 332. The organic matter in the infusion changes the iodine so that it no longer gives a test with starch. The benefit derived from the iodine is questionable. 333. The glycerin was added to the tincture of myrrh, then the solution of potassium chlorate in small amounts with con- tinued shaking, and the tincture of iron last. Tincture of iron gives a dark green-brown color with tincture of myrrh. Water precipitates the resinous matter from the tincture of myrrh, and it forms in masses that cannot be evenly sus- pended. It seems to make but little difference whether the alcoholic mixture is added to the aqueous or the aqueous to the alcoholic. By using honey instead of glycerin the resin is separated but does not form masses, consequently it can be €venly distributed through the liquid. 334. The fluid extracts and elixir are sufBciently acid so that chemical reaction takes place between the potassium nitrite and the organic matter. Considerable effervescence ensues and continues for some time. Oxides of nitrogen are given off. A slight precipitate forms on standing. Probably much of the physiological activity of the mixture is destroyed by the chemical reaction. 335. A mixture of these ingredients quite quickly separates into two layers, the lower one being about one fourth the 264 INCOMPATIBILITIES IN PRESCRIPTIONS. total volume. There is not sufficient alcohol to dissolve the other liquids. There is no effervescence at first, but if the bottle is tightly corked it may be burst by the gas which is slowly evolved. The liquid becomes red-brown on standing. 336. A clear solution was obtained which had at first a dark violet color. The color soon changed to brown, and in a few hours a dark-brown precipitate began to form. The amount of precipitate continued to increase for some time. It was filtered out, thoroughly washed with water, and heated with water acidulated with hydrochloric acid; part went into solution and part remained undissolved. The filtrate showed the presence of iron. The part left undissolved is probably some oxidation product of carbolic acid, produced by the chlorine liberated by the acid in the tincture acting on the potassium chlorate. 337. The color of this mixture is brown at first, due to the free iodine. The iodine soon combines with the free oleic acid., forming addition products which are nearly colorless. 338. There is a sufficient amount of water to dissolve the potas- sium salts and the solution remains clear for a time after the spirit is added. It is not long, however, before crystals begin to separate. The alcohol in the spirit throws the potassium chlorate out of solution. 339. When the two prescriptions are mixed in the proportion^ as directed the result is almost a mass. Reaction takes place between silver nitrate and potassium iodide, forming the in- soluble silver iodide. It is customary to filter all preparations INCOMPATIBILITIES IN PRESCRIPTIONS. 265; intended to be dropped into the eyes, but in this case the pre- scriber wanted the solid matter left in. The solution marked No. I, containing. silver nitrate, began to darken within an hour, due to the reduction of silver. This reduction con- tinued for some time. Solution No. 2 turned yellow in a few days. 340. The alkaloid morphine is liberated and is dissolved to some extent by the chloroform. Only a small part of the chloroform is dissolved 'by the water, the remaining part goes to the bottom. The oils liberated from the aromatic spirit by water are dissolved in the chloroform. This prescription was dispensed with a " Shake well " label. 341. Filled as directed this prescription gives a nearly colorless mixture which does not give a test for free iodine. On stand- ing two layers are formed, the upper being about one third of the volume of the lower. The upper layer consists chiefly of turpentine, while the lower consists of the alcohol contain- ing some oil of turpentine and an iodide of mercury. Leav- ing out either the turpentine or mercuric chloride, the iodine is not all reduced. If the mercuric chloride is left out the lower layer is smaller in volume and is nearly colorless, while the upper one is chiefly alcohol containing free iodine. The turpentine is the principal factor in reducing the iodine. The mercuric chloride perhaps acts as a carrier or acts by break- ing up the compound which iodine forms with the oil, thereby allowing the oil to combine with more iodine. 342. The sodium bromide and antipyrin were dissolved in syrup of lemon and a part of the water and the chloral hydrate in the balance of the water. The two solutions were mixed 366 INCOMPATIBILITIES IN PRESCRIPTIONS. and a turbidity was produced. On allowing the mixture to stand it separated into two layers, the lower being small in volume, yellow brown, and of an oily nature, and was prob- ably a compound of antipyrin and chloral hydrate. 343. Although a clear solution is produced at first, within a few minutes a crystalline precipitate begins to form. Piperazin is quite strongly alkaline and causes a precipitation of the strychnine. As written this should be considered a dangerous combination. The difficulty can be remedied by neutralizing the piperazin solution with dilute sulphuric acid. 344. When chloral hydrate and ammonol are rubbed together a liquid is produced. The prescription was filled by massing with powdered liquorice root. In such a case it is preferable to use a white absorbent powder. 345. A mixture of these ingredients makes a clear colorless solution at first. Antipyrin destroys the fluorescence of quin- ine sulphate. A white amorphous precipitate forms in a day or two and increases in amount for some time. If the pre- scription is filled, using distilled water instead of cinnamon "water, no precipitation results. The trouble seems to be due to antipyrin, sulphuric acid, and cinnamon water, since a mixture of any two or three ingredients of the prescription other than the combination mentioned does not precipitate. 346. Trional and salol produce a soft mass when rubbed to- ;gether, and a drying powder is necessary. INCOMPATIBILITIES IN PRESCRIPTIONS. 267 347. This prescription was filled by mixing the first four in- gredients and putting into capsules and then dropping in the tincture. The next day the box in which the capsules were dispensed was brought back, the capsules had been dis- solved. Sodium bromide attracts moisture from the atmos- phere. Antipyrin with caffeine citrate makes a mixture that forms a sticky mass on standing a few hours. A mixture of all the ingredients makes a damp powder at first, but in a few hours it becomes almost liquid. A large amount of dry- ing powder is necessary. 348. The bottle containing this mixture should not be stop- pered tightly or it may be burst. Infusion of digitalis is acid in reaction and slowly liberates carbon dioxide gas from am- monium carbonate. 349. There is a sufificient amount of alcohol and water to pre- vent the gold salt from precipitating strychnine. However, the gold is reduced in a few hours, largely by the alcohol but partly by the syrup. The gold as precipitated has a purplish color by transmitted light but yellow or brown by reflected light. 350. The potassium acetate was dissolved in water and the spirit added. Efifervescence ensued and continued for a few minutes, but ceased after several shakings. Alcohol effer- vesces a little when mixed with water, but not nearly as much as the above mixture did. One writer (Scoville, 223) says that nitrous acid converts acetates into carbon monoxide and other gases. This explanation is not satisfactory since about 268 INCOMPATIBILITIES IN PRESCRIPTIONS. as much effervescence results when spirit of nitrous ether is added to a strong solution of Rochelle salt, sodium chloride, or potassium nitrate. It has been suggested that the potas- sium acetate or other salt throws the ethyl nitrite out of solu- tion in the mixture of alcohol and water and that the vola- tilization of the ethyl nitrite is the cause of the effervescence. There is much less effervescence when the solutions have been well chilled before mixing. INCOMPATIBILITIES IN PRESCRIPTIONS. 269 2/0 INCOMPATIBILITIES IN PRESCRIPTIONS. TABLE OF SOLUBILITIES* IN WATER, ALCOHOL, ETHER. CHLOROFORM AND GLYCERIN, OF MEDI- CINAL SUBSTANCES OFFICIAL IN THE U. S. PHARMACOPOEIA, IN- CLUDING MANY OTHERS OF COMMON OR FREQUENT USE. Abbreviations— J., soluble; i/. j., very soluble; j/.. sparingly; a., all proportions; j/., slightly; ins., insoluble; «. ins., nearly insoluble; t/ec, decomposed. Medicinal Substances. One part is soluble in [at 59° F. (.5° C.) U. S. P. Standard Temperature] Acacia Acetanilid Acid, Arsenous Benzoic Boric Carbolic Chromic Citric Gallic Lactic Meconic Oleic Oxalic Phosphoric, Glacial Picric Pyrogallic (see Pyrogallol). Salicylic Stearic . Tannic Tartaric Valerianic Aconitine Alcohol Amylic Methylic Aloin Alum Aluminum Hydrate Sulphate Ammonium Benzoate Bicarbonate Bromide Carbonate Chloride Iodide Nitrate Pliosphate Sulphate Valerianate Amyl Nitrite Antimony Oxide Sulphide and Potassium Tartrate. . . . Antipyrin Apomorphine Hydrochloride Aristol Arsenic Iodide Atropine Sulphate Balsam Peru Tolu Barium Carbonate Chloride Bebeerine Sulphate Benzanilid Berberine Hydrochloride Water. 194 80 500 25.6 »5 V. s. 0.63 100 a. sp. ins. 8.17 V. s. 450 ins. '•5 5 3 I 0.5 4 1.2 V. S. ins. n. ins. ins. 17 I 6.8 ins. 7 130 0.4 Alcohol. 2-5 6000 ins. 5 141 2 15 V. s. dec. 1.61 5 a. V. s. a. 2-5 V. s. 0.6 2-5 20 ins. ins. ins. 28 ins. 30 dec. ins. sp. 45 sp. s. n. ins. ins. sol. V. s. 58 250 sp. Ether. dec. n. ins. ins. a. 470 ins, ins. ins. ins. Chloroform. V. s. 7 V. s. ins. n. ins. ins. ins. 80 s. n. ins. n. ins. 3 3 ins. ins. ins. ins. 600 ins. 50 si. s. sol. 16 2270 sp. s. ins. ins. si. 694 Glycerin. 2-S ins. ins. ins. ♦ Taken frcra " Era Dose Book." INCOMPATIBILITIES IN PRESCRIPTIONS. 271 TABLE OF SOLUBILITIES— (Cb«/««w/' 4 $2 00 1 50 1 25 1 25 1 25 6 00 3 00 5 GO 1 50 CoLii's ludiciitors aud Test-papers 12ii)o ■Ciafts's Qualilative Analysis. 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