A 
 
 Laboratory Manual 
 
 W. R. ORNDORFF 
 
 D. C. HEATH & CO. 
 
 BOSTON. NEW YORK. CHICAOO. LONDON 
 
Olnrti^U Itttersttg 
 
 THE CALDWELL COLLECTION 
 
 
 THE GIFT OF THE FAMILY OF 
 
 GEORGE CHAPMAN CALDWELL 
 
 TO THE 
 
 DEPARTMENT OF CHEMISTRY 
 whose senior Professor he was from 1868 to 1903 
 
Cornell University Library 
 QD 261.074 
 
 A laboratory manual, containing directio 
 
 3 1924 003 038 357 
 
Cornell University 
 Library 
 
 The original of tliis book is in 
 tine Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31924003038357 
 
A 
 
 LABORATORY MANUAL 
 
 ooHTAimita 
 
 DIRECTIONS FOR A COURSE OE EXPERIMENTS 
 IN ORGANIC CHEMISTRY 
 
 SYSTEMATICALLY ARRANGED TO ACCOMPANY 
 REMSEN'S ORGANIC CHEMISTRY 
 
 W. E. OENDORFF, A.B., Ph.D. 
 
 Assistant PEorESSOR op Chemistbt in Coknell Uniteksitt 
 
 • BOSTON, U.S.A. 
 
 D. C. vHEATH & CO., PUBLISHERS 
 
 1393 
 
 6 
 
CoPTBiaHT, 1893, 
 Bt W. R, ORNDORFF. 
 
 Printed by C. H. Heintzemann, Boston, Mass, 
 
PREFACE. 
 
 At the author's request I have carefully examined 
 this Manual ; and, as a result, I have recommended its 
 publication, in the belief that it will be a valuable 
 adjunct to my "Introduction to the Study of the 
 Compounds of Carbon." Great care has evidently 
 been taken to determine the best conditions for each 
 experiment ; and, in many cases, the directions given 
 are undoubtedly better than those given in my book. 
 This is largely due to the fact that the author has, 
 for a number of years, had charge of the work of 
 preparation of compounds of carbon in a large labora- 
 tory ; and he lias therefore had an excellent oppor- 
 tunity thoroughly to test different methods, — an 
 opportunity which he has well utilized. 
 
 IRA REMSEN. 
 BAi.TmoBB, Md., March 6, 1893. 
 
EXPERIMENT 1. 
 
 FRACTIOITAI. DISTILLATION. 
 
 Fit up an apparatus like the one shown in Fig. 1 
 (text-book, page 5), using a 1-liter distilling-flask 
 (Fig. 2, text-book), in place of the flask and ther- 
 mometer tube. Add 300 c.c. of alcohol and 300 c.c. 
 of water to the flask, and separate the two by frac- 
 tional distillation, following closely the directions 
 given on pages 6 and 7 of the text-book. Distil 
 slowly and regularly. Measure each fraction, and 
 the residue left in the flask at the end of each 
 series of distillations. Fill in the blanks in the 
 following table, and draw your own conclusions 
 from the results. 
 
 
 DISTILLATIONS. 
 
 
 1. 
 
 8. 
 
 3. 
 
 4. 
 
 5. 
 
 78°- 83° • 
 83°- 88° 
 88°- 93° 
 93°- 98° 
 98°-100° 
 Residues 
 Totals 
 
 
 
 
 
 
 For further information regarding all kinds of 
 distillation, and for the methods of determining 
 boiling-points, the student is referred to Lassar- 
 Cohn's very valuable book, " Arbeitsmethoden fiir 
 Organisch-Chemische Laboratorien " (Voss, Leipzig, 
 1891). 
 
EXPERIMENT 2. 
 
 DETERMINATION OP MELTING-POINTS. 
 
 Determine the melting-points of the substances 
 given below, proceeding as directed in the text-book, 
 
 ■page 9, using, however, the 
 apparatus here figured : A 
 is a pear-shaped flask, of 
 100 CO. capacity, f filled 
 with colorless concentrated 
 sulphuric acid. The ther- 
 mometer is held in place 
 by a loosely fitting cork 
 with a groove filed in it. 
 The capillary tube is fas- 
 tened to the thermometer 
 by a rubber band, or, better, 
 by a small piece of plati- 
 num wire, so that the sub- 
 stance and the bulb of the 
 thermometer are side by 
 side. By fastening two capillary tubes, one on each 
 side of the thermometer, two determinations may be 
 made at once. Should the sulphuric acid become 
 dark colored (from the organic matter suspended in 
 it), it may be rendered colorless by removing the 
 thermometer, adding a small quantity of concen- 
 trated nitric acid, and heating until the nitric acid 
 has been driven off. (Hood.) For further details 
 
concerning melting-point determinations, see Lassar- 
 Cohn's book, page 75. 
 
 SUBSTANCES. 
 
 MEMING-POIXTS. 
 
 ObserTed. 
 
 Given in Text. 
 
 Naphthalene. 
 Urea. 
 
 Succinic acid. 
 Anthracene. 
 Anthraquinone. 
 
 
 
EXPERIMENT 3. 
 
 MARSH GAS. 
 
 . Grind together intimately 20 grams of fused sodium 
 acetate and 40 grams of powdered soda-lime. Heat 
 the mixture in an iron or copper retort with a triple 
 burner. Collect the gas evolved over water in wide- 
 mouthed cylinders of 200 c.c. capacity. What is left 
 in the retort ? Prove it. Write out the reaction. 
 
 Determine the properties of the gas, including 
 color, odor, specific gravity (lighter or heavier than 
 air), inflammability, solubility, etc. Mix one volume 
 of marsh gas and two volumes of oxygen and ex- 
 plode by applying a lighted taper. Why are the gases 
 mixed in this proportion? What are the products 
 of the explosion? 
 
 Caution. — In worTcing with gases see that all joints 
 of the apparatus are tight before beginning the experi- 
 ment. 
 
EXPERIMENT 4. 
 CHLOROFORM. 
 
 275 grams of bleaching-powder and 800 c.c. 
 of water are put into a 3-liter balloon-flask, and 
 thoroughly mixed. The flask is closed with a 
 3-hole rubber stopper. Through one hole passes 
 a separating funnel, reaching to the bottom of the 
 flask ; through the second, a tube bent at right 
 angles, and also reaching to the bottom of the 
 flask; and through the third, the exit tube. Con- 
 nect the flask with the condenser and receiver, heat 
 on a water-bath, and add gradually, through the 
 separating funnel, a mixture of 22 grams of ace- 
 tone and 70 c.c. of water, shaking the flask con- 
 stantly during the addition of the acetone and 
 water. After all the acetone has been added 
 and the reaction is completed, steam is passed in 
 through the tube reaching to the bottom of the 
 flask, and the distillation in steam is continued as 
 long as chloroform distils with the water. 
 
 Separate the chloroform from the water by means 
 of a separating funnel ; wash it with dilute caustic 
 soda solution (?), and then with water (?). Remove 
 the water completely, add an equal volume of con- 
 centrated sulphuric acid (?), and shake together 
 in a Separating funnel. Drain off completely the 
 sulphuric acid and distil the chloroform, noting the 
 boiling-point. 
 
Save a specimen of the chloroform, and determine 
 its properties, — color, odor, taste, boiling-point, 
 specific gravity (lighter or heavier than water), 
 solubility, inflammability. 
 
 What is formed when chloroform is heated with 
 an alcoholic solution of caustic potash ? 
 
 Write out reactions after acetone and chloral 
 have been studied. 
 
EXPERIMENT 6.1 
 
 IODOFORM. 
 1. 
 
 Dissolve 15 grams of potassium carbonate in 100 
 c.c. of water, filter the solution if necessary, and 
 add 16 grams of alcohol (94%). The flask contain- 
 ing the solution is warmed to 70°C, and 20 grams of 
 iodine are then gradually added, with constant shaking 
 of the flask. A gas is given off ; what is it ? Filter 
 off the iodoform, wash with water, dry in the air on 
 filter-paper, and recrystallize from alcohol. Deter- 
 mine its melting-point, solubility in water, alcohol, 
 ether, carbon bisulphide; crystal form, taste, odor, 
 and color. The filtrate from the iodoform is evap- 
 orated to crystallization and the crystals examined. 
 What are they? Prove it. 
 
 Save a specimen of the crystallized iodoform and 
 the potassium iodide. 
 
 Reactions are to be written out after chloral has 
 been considered. 
 
 1 Make iodoform by either of tlie two metliods here given. The 
 second has given the better results in this laboratory. 
 
EXPERIMENT 6. 
 IODOFORM. 
 
 2. 
 
 Dissolve 25 grams of potassium iodide in 600 
 c.c. of water and add 5 grams of acetone. To this 
 mixture add, through a dropping-funnel or burette, 
 with constant shaking, a dilute solution of sodium 
 hypochlorite as long as a precipitate is formed. Allow 
 the precipitate to settle, decant off the liquid, wash 
 with water two or three times, filter, drain thor^ 
 oughly, dry on filter-paper, and recrystallize from 
 alcohol. Does any iodide remain in solution ? De< 
 termine the melting-point, solubility in water, alco- 
 hol, ether, carbon bisulphide, etc.; crystal form, 
 taste, odor, and color. 
 
 Save a specimen of the crystallized iodoform. Write 
 out the reactions after chloral and acetone have been 
 considered. 
 
 The solution of sodium hypochlorite used in this 
 experiment may be readily made by precipitating 
 all the calcium in a solution of bleaching-powder 
 (chloride of lime) with a solution of sodium carbo- 
 nate. A slight excess of sodium carbonate will not 
 interfere with the reaction. 
 
EXPERIMENT 6.1 
 
 ETHVL BROMIDE. 
 
 (Hood.) 
 1. 
 
 10 grams of dry (?) amorphous phosphorus and 60 
 grams of absolute (?) alcohol are brought together 
 in a 500 c.c. round-bottomed flask which is kept* cold 
 by ice-water ; 60 grams (19 c.c.) of bromine are then 
 gradually added through a separating-funnel, drop 
 by drop, with constant shaking of the flask. After 
 all the bromine has been added, the flask is connected 
 with a return condenser (see Fig. 8, page 70, text- 
 book) and gently heated on a water-bath until the 
 reaction is completed. The condenser is then turned 
 down, and the ethyl bromide distilled off. Wash this 
 with dilute caustic soda solution (?), then with 
 water ; drain off the water, and dry by warming 
 slightly with fused calcium chloride, using a return 
 condenser (?). Pour off from the calcium chloride 
 into a dry distilling-flask and distil, noting the 
 boiling-point. 
 
 Determine color, odor, taste, specific gravity 
 (heavier or lighter than water), inflammability 
 (Hood). Save specimen of the pure product. What 
 
 1 Either of the two methods given may he used to prepare 
 ethyl bromide; the second has given better results in this 
 laboratory. 
 
is left in the flask in which the ethyl bromide was 
 made ? Prove it. Add a few drops of ethyl bromide 
 to some silver nitrate solution and heat. Explain 
 what takes place. Write out all reactions. 
 
EXPERIMENT 6. 
 
 ETHYL BROMIDIi. 
 
 (Hood.) 
 2. 
 
 100 grams of finely powdered potassium bromide 
 are placed in a 250 c.c. distilling-flask, and a cooled 
 mixture of 42 grams of absolute alcohol (96% will 
 do) and 83 grams of concentrated sulphuric acid is 
 slowly added. The flask is then connected with the 
 condenser and heated on a sand-bath until all the 
 ethyl bromide has been distilled. The ethyl bromide 
 is then separated from the water, washed first with 
 dilute caustic soda solution, then with water, and 
 dried by warming on a water-bath with fused, cal- 
 cium chloride (using a return condenser — see 
 Fig. 8, page 70, text-book). The product is then 
 distilled, carefully noting the boiling-point. Save a 
 specimen of the pure ethyl bromide. 
 
 Determine its physical properties : color, taste, 
 odor, specific gravity (lighter or heavier than 
 water), inflammability (Hood), boiling-point, etc. 
 Determine the action of silver nitrate solution at 
 boiling heat on ethyl bromide. What remains in the 
 flask in which the ethyl bromide was made ? Prove 
 it. Write out all reactions. 
 
EXPERIMENT 7. 
 FERMENTATION OF GLUCOSE. 
 
 Dissolve 150 grams of glucose in about IJ liters of 
 water, add 60 c.c. of a solution of Pasteur salts.^ 
 Put the mixture into a 2-liter flask, add ^ cake of 
 compressed yeast (cut fine), and warm to 25° C. on a 
 water-bath. Connect the flask with a cylinder con- 
 taining limewater (protected from the air by a layer 
 of kerosene or benzene). Keep the temperature as 
 near 25° as possible (by warming on a water-bath), 
 until fermentation ceases; then allow the yeast to 
 settle, and draw off the clear liquid. Distil off 
 500 c.c. of this, using a Hempel distilling-tube (?), 
 and test the distillate for alcohol (see Roscoe and 
 Schorlemmer's Treatise on Chemistry, Vol. III. Part 
 I. page 318). Write out all reactions. 
 
 Explain why Pasteur salts are used and why the 
 limewater must be protected from the air. What 
 gas comes off ? Will the alcohol burn ? Try it. 
 
 For further information on the subject of fermen- 
 tation the student is referred to Schutzenberger's 
 book on Fermentation. 
 
 1 The formula for Pasteur salts, based on an analysis of the 
 inorganic constituents of the yeast plant, is as follows : — 
 
 Potassium phosphate 
 
 2.00 pts 
 
 Calcium " 
 
 0.20 " 
 
 Magnesium sulphate 
 
 0.20 " 
 
 Ammonium tartrate 
 
 . 10.00 " 
 
 "Water 
 
 . 857.60 " 
 
EXPERIMENT 8. 
 
 ABSOLUTE ALCOHOI.. 
 
 Heat, on the water-bath, 1 liter of alcohol (95 %) 
 with 500 grains of quicklime, broken into small 
 lumps (not powder), in a 3-liter short-necked balloon 
 flask provided with a return condenser (see text- 
 book, page 70, Fig. 8). After boiling the alcohol with 
 the lime for two hours, distil off the alcohol, and de- 
 termine whether it is free from water (see Roscoe 
 and Schorlemmer's Treatise on Chemistry, Vol. III. 
 Part I. page 298 ; and Beilstein's " Organische 
 Chemie," Vol. I. page 237). If not, repeat the 
 process with the distillate. 
 
 Explain the process, and determine the specific 
 gravity of the alcohol and the per cent of water it 
 contains. 
 
 Determine the properties of pure alcohol, includ- 
 ing color, odor, taste, boiling-point, inflammability. 
 Does its vapor mixed with air explode ? Try it. 
 Does it solidify when cooled? What use is made 
 of this fact? Is alcohol a good solvent? Try it. 
 
 The student is recommended to read the chapter 
 on alcoholometry and the methods of determining 
 the amount of alcohol in wines, beer, etc., in Roscoe 
 and Schorlemmer's Treatise on Chemistry, Vol. III. 
 Part I. page 301. 
 
EXPERIMENT 9. 
 
 CALCIUM ETHTL SULPHATE. 
 
 Add 98 grams of concentrated sulphuric acid to 
 138 grams of absolute alcohol without cooling, and 
 heat the mixture on the water or steam bath for a 
 quarter of an hour. After the mixture is cold, pour 
 it slowly, and with constant stirring, into a porcelain 
 dish containing crushed ice or snow (?). Then 
 dilute with ice-water to about a liter and a half. The 
 acid is now nearly neutralized by adding slaked lime 
 or precipitated chalk, ice being added from time to 
 time to prevent any rise of temperature (?). The 
 solution is then filtered off from the calcium sulphate 
 through a muslin filter stretched on a wooden frame, 
 or, better, by the method of reverse filtration. The 
 apparatus for this latter process consists of a small 
 funnel which is covered with white cotton cloth, and 
 which is connected by a rubber tube with a bottle, 
 the bottle in turn being connected with a suction- 
 pump. The funnel is placed in the mixture to be 
 filtered, and the pump started. The liquid is drawn 
 through the funnel into the bottle, and is quickly 
 and completely filtered. The precipitate is then 
 treated with \ liter of cold water and the liquid again 
 filtered off. Clear limewater is now added to the 
 combined filtrates to alkaline reaction (?), and this 
 solution is evaporated to crystallization on the steam 
 or water-bath, taking care to filter off the calcium 
 
sulphate which separates out as the solution is con- 
 centrated. Explain. After the first crop of crystals 
 has formed, filter them off, using a Witt plate and a 
 filtering-flask connected with a pump, and repeat the 
 process with the mother liquor. Drain the crystals . 
 thoroughly and dry on drying-paper. 
 
 Determine the color, taste, crystal form, solubil- 
 ity, etc., of the crystals obtained. Save a specimen. 
 Does the salt contain water of crystallization ? Try 
 it. Does it contain carbon ? Prove it. 
 
 Write out all reactions. 
 
EXPERIMENT 10. 
 
 ETHER. 
 
 Arrange an apparatus like the one shown in the figure 
 below. 
 
 A is a round-bottomed, wide-necked flask of 2 
 liters' capacity. 
 
 ^ is a cylindrical separating-funnel reaching" to 
 the bottom of A. 
 
 C, a short thermometer, the bulb of which must 
 dip Tselow the surface of the liquid. 
 
 D, an adapter which is connected with the receiver 
 by a doubly bored stopper. 
 
 U, a receiver, which must be surrounded with a 
 freezing mixture (ice and salt). 
 
 Into the flask A put a cooled mixture of 306 grams 
 of concentrated sulphuric acid and 170 grams of 
 alcohol (90%). Heat the mixture in the flask A un- 
 til the temperature reaches 140° C. Then cautiously 
 open the stopcock of the separating-funnel and let a 
 
slow stream of alcohol in the form of vapor bubble 
 through the liquid, regulating the flow of alcohol so 
 that the temperature of the mixture is kept as nearly 
 140° C. as possible (not below 140° and not above 
 145°). When 500 grams of alcohol have been run in, 
 the operation is stopped. The distillate consists of 
 two layers, and contains, besides ether, water, alcohol, , 
 and sulphurous acid. The watery layer is removed 
 by means of a liter separating-funnel, and the ether 
 is washed first with dilute caustic soda solution (?), 
 then two or three times with small quantities of dis- 
 tilled water (?). The washed ether is now treated 
 with one-half its weight of fused calcium chloride, 
 and distilled on a water-bath through a Hempel dis- 
 tilling-tube, taking care that the temperature does 
 not rise above 50° C. The distillate must be kept 
 cold by ice-water. Weigh the ether obtained and see 
 how the yield accords with that required by theory. 
 
 Determine the boiling-point, specific gravity, color, 
 solubility in alcohol and water, taste, and odor. 
 Place a few drops on the hand and note the effect 
 produced. Mix a little in a wide, strong cylinder 
 with air, and apply a lighted taper. Explain. Is it 
 a good solvent ? Try it. Does water dissolve ether ? 
 Does ether dissolve water ? 
 
 Write out all reactions. Save a specimen of ether. 
 
 Caution. — In worJcinff with ether always avoid the 
 neighborhood of flames (?). 
 
EXPERIMENT 11. 
 
 Put a few cubic centimeters of ether into a small 
 evaporating-dish and put the dish on a sand-bath. 
 Apply a flame. Note the result. 
 
 What are the products of the combustion ? Prove it. 
 
 EXPERIMENT 12. 
 
 Into a thin glass test-tube put 5 or 10 c.c. of water 
 and place the tube in a small beaker containing 
 some ether. Through a glass tube, just reaching to 
 the surface of the ether, pass air from a foot bellows 
 or a blast. In a few moments the water in the test- 
 tube will be frozen. Explain. 
 
 EXPERIMENT J3. 
 
 ALDEHYDE. 
 
 Dissolve 5 grams of potassium bichromate in water 
 and add gradually 15 c.c. of concentrated sulphuric 
 acid. Is there any change of color ? • What is formed ? 
 Now add a few cubic centimeters of alcohol and warm 
 the tube. Notice the odor. What is formed? Does 
 the solution change color? Explain. What has 
 become of the potassium bichromate and the alcohol ? 
 What is left in the solution? Prove it and write out 
 all reactions. 
 
EXPERIMENT 14. 
 ALDEHYDE. 
 
 225 grams of potassium bichromate (in small pieces 
 not powdered) are placed in a 3-liter round-bottomed 
 flask, and the flask surrounded with a freezing mix- 
 ture. Then add through a separa ting-funnel a cool 
 mixture of 125 grams of alcohol (90%), 900 c.c. 
 of water, and 300 grams of concentrated sulphuric 
 acid, shaking the flask during the addition of the mix- 
 ture, so as to avoid any great rise of temperature. 
 The flask is then removed from the freezing mixture, 
 connected with a Hempel distilling-tube (40 to 50 
 cm. long), a condenser, and receiver, the latter sur- 
 rounded with a freezing mixture. Heat the flask 
 gently and collect the distillate, taking care that 
 the temperature shown by the thermometer in the , 
 Hempel tube does not exceed 50° C. Distil until 
 aldehyde ceases to come off. 
 
 Determine the taste, odor, color, boiling-point, solu- 
 bility, etc., of the aldehyde obtained. Is it lighter or 
 heavier than water ? Does it dissolve iodine, sulphur, 
 phosphorus ? Try it. Heat a few drops of aldehyde 
 with caustic potash solution. Note change of color 
 and odor (characteristic of aldehyde). Save a few 
 drops for Experiment 15. 
 
 Cool 10 c.c. of this aldehyde in a small flask in a 
 freezing mixture and pass in a few bubbles of hydro- 
 chloric acid gas. What takes place ? Explain. Fil- 
 
ter off the crystals, wash them with alcohol, and cool 
 the first filtrate in a mixture of concentrated hydro- 
 chloric acid and crushed ice (or ice and crystallized 
 calcium chloride). Note result. Explain. To 10 
 c.c. of the aldehyde add 20 c.c. of anhydrous ether, 
 cool in a freezing mixture, and saturate with dry 
 ammonia gas, obtained by heating a concentrated 
 solution of aqueous ammonia and passing the gas 
 evolved through a cylinder filled with quicklime or 
 soda-lime (?). Note result. Explain. Filter off the 
 crystals, wash with ether, and dry on drying paper. 
 Let the filtrate evaporate spontaneously in a crystal- 
 lyzing-dish, when more crystals will be obtained. 
 
 Save specimens of aldehyde, nietaldehyde, paralde- 
 hyde, and aldehyde ammonia. 
 
 Write out all reactions. 
 
EXPERIMENT 15. 
 
 DETECTION OF ALDEHTDE. 
 
 Take 10 c.c. of a solution of silver nitrate, add 
 cautiously drop by drop a dilute solution of ammonia 
 until the silver oxide first precipitated is just dissolved, 
 taking care to avoid any excess of ammonia. An 
 ammoniacal solution of silver oxide is thus obtained. 
 
 Clean a test-tube thoroughly by boiling some con- 
 centrated nitric acid in it, pouring out the acid and 
 washing with distilled water. Heat the ammoniacal 
 silver oxide solution to boiling in the cleaned test- 
 tube, then add a drop of the aqueous solution of 
 the aldehyde obtained in Experiment 14, noting the 
 result. Explain. What becomes of the aldehyde? 
 What use is made of this method in the arts ? 
 
 Test the delicacy of this reaction both for aldehyde 
 and for silver. (See in this connection Roscoe and 
 Schorlemmer's Treatise on Chemistry, Vol. III. page 
 478.) 
 
 Write out all reactions and save a specimen of the 
 silver mirror. 
 
EXPERIMENT 16. 
 
 FORMIC ACID. 
 
 Into a 600 c.c. dry distilling-flask put 200 grams of 
 crystallized oxalic acid and 200 grams of anhydrous 
 glycerin (if the glycerin is not anhydrous, heat it in 
 a porcelain dish under the hood to 175° C. for an hour 
 or two). Insert a thermometer through the cork, so 
 that the bulb dips below the surface of the glycerin, 
 and connect the flask with a condenser and a receiver. 
 Heat gently with a burner, keeping the temperature 
 of the liquid between 100°-115° C. What gas is given 
 off ? When this gas ceases to be evolved, and after 
 the contents of the flask have cooled to 75°, add 50 
 grams more of the crystallized oxalic acid, and heat as 
 before. Repeat this addition of oxalic acid until 250 
 c.c. of distillate 'have collected in the receiver. Put 
 the glycerin into the bottle marked " Glycerin Resi- 
 dues," and set aside 25 c.c. of the distillate for the 
 experiments given below. Divide the rest into three 
 portions. Neutralize one portion with chalk or slaked 
 lime, filter, evaporate to crystallization, and save speci- 
 men of the calcium salt. Warm the second portion 
 with a slight excess of lead carbonate or oxide, decant 
 through a filter, and extract the precipitate two or 
 three times with boiling water (?). Evaporate the 
 combined filtrates to crystallization and save a speci- 
 men of the lead salt. Heat the third portion until 
 saturated with freshly precipitated copper hydroxide 
 
(obtained by precipitating a solution of copper sul- 
 phate with caustic soda solution and washing the 
 precipitate thoroughly with water), filter, evaporate 
 the filtrate to crystallization, and save a specimen of 
 the copper salt. 
 
 With the 25 c.c. of the distillate perform the fol- 
 lowing experiments : — 
 (a) Heat a small quantity with some mercuric 
 
 oxide and note the result. Explain. 
 (6) Heat some with a solution of silver nitrate 
 and describe and explain what takes place. 
 (Explain why these two reactions are charac- 
 teristic of formic acid.) 
 Describe both the physical and chemical properties 
 of all the salts made; save specimens of all and of 
 the distillate. Write out all reactions. 
 
 (Use the material in the bottle marked " Glycerin 
 Residues" to start with, if it is available, instead 
 of glycerin itself, and add only 50 grams of oxalic 
 acid at a time.) 
 
EXPERIMENT 17. 
 
 ACETIC ACID. 
 
 150 grams of fused sodium acetate are powdered 
 and put into a 500 c.c. dry distilling-flask. The flask 
 is cooled, and 180 grams of concentrated sulphuric 
 acid (sp. gr. 1.842) are gradually added through a 
 funnel-tube reaching to the bottom of the flask. The 
 flask is then connected with a condenser and receiver 
 and heated on a sand-bath. The distillate is sub- 
 jected to fractional distillation, using a short Hempel 
 distilling-tube, or, better, a distilling-flask,^ with a 
 column of glass beads in the neck (see figure). 
 
 First an aqueous acid passes over 
 and is collected separately, but 
 between 117° and 119° the anhy- 
 drous acid distils. Cool this distil- 
 late (between 117°-119°) with ice- 
 water, and note what takes place. 
 Save specimen of the glacial acid. 
 Why is the first distillate not anhy- 
 drous ? 
 
 A portion of the first distillate of 
 the aqueous acid is carefully neu- 
 tralized with caustic soda solution 
 and divided into four portions. One portion is 
 heated to boiling, and then a slight excess of mer- 
 
 1 These flasks, which' are exceedingly convenient for fractional 
 distillation, may be procured from Gerhardt, or from Eimer & 
 Amend. 
 
curous nitrate solution added. Explain what takes 
 place. The second portion is also heated to boil- 
 ing, and a tolerably concentrated solution of silver 
 nitrate added. Note what takes place. Explain. 
 The third portion is evaporated to dryness, on a 
 steam or water bath, with some powdered arsenic 
 trioxide, and a little of the resulting mass heated 
 in a test-tube when the characteristic odor of cacodyl 
 oxide is given off. Explain. To the fourth portion 
 add a little concentrated sulphuric acid and alcohol, 
 and heat. Notice the odor. Explain. 
 
 Write out all reactions, and show how you could 
 distinguish between formic and acetic acids. 
 
 Describe the properties of acetic acid, and give 
 some of the methods by which this substance may 
 be detected in solution. 
 
EXPERIMENT 18. 
 
 Make up a solution containing ferric chloride, alu- 
 minum, manganese, zinc, cobalt, and nickel chlorides. 
 Nearly neutralize any free acid present with a solution 
 of sodium carbonate (?). If a precipitate is formed 
 dissolve in a small quantity of acetic acid. Add 
 enough of a concentrated solution of sodium acetate 
 to convert all the metals present into acetates (taking 
 care to avoid a large excess of the reagent), and boil 
 the solution. Note what takes place. What is vola- 
 tilized ? Explain. Filter off the precipitate and test 
 the filtrate for iron, aluminum, and the other metals. 
 Draw your own conclusions from the results, and 
 show how these facts could^be utilized in analytical 
 chemistry. Could you separate ferrous iron from 
 ferric by this method? Explain. 
 
 EXPERIMENT 19. 
 
 To a mixture of equal parts of acetic acid and alco- 
 hol in a test-tube add some concentrated sulphuric 
 acid, and heat. Note what takes place. To what 
 is the pleasant and characteristic odor due ? What 
 part does the sulphuric acid play? 
 
 Write out reactions, and determine the delicacy 
 of this reaction for the detection of small quantities 
 of acetic acid and salts of acetic acid. 
 
EXPERIMENT 20. 
 
 ACETYL CHLORIDi:. 
 
 (Hood.) 
 
 43 grams of glacial acetic acid are put into a dry (?) 
 250 c.c. round-bottomed flask, the flask cooled with 
 ice-water, and 65 grams of phosphorus trichloride 
 (weigh this under the hood (?)) are gradually added, 
 with constant shaking. Connect the flask with a 
 return condenser, and heat it on a water-bath to 50°- 
 60° C. until almost all the hydrochloric acid gas has 
 been expelled. The condenser is then turned down 
 and the acetyl chloride distilled off, care being taken 
 to protect the distillate from the action of the moist- 
 ure in the air by means of a tube containing calcium 
 chloride. The distillate is then placed in a small, dry 
 distilling-flask, and redistilled with the same precau- 
 tions as before. 
 
 What remains in the flask in which the acetyl 
 chloride was made? Prove it. Save this material 
 and put into proper bottle. 
 
 Determine all the properties of acetyl chloride, 
 including color, odor, boiling-point, action on moist 
 air. Add a few drops to some water in a test-tube 
 and note what takes place. Explain. Put aside some 
 of the chloride for Experiment 21. Save specimen 
 in a small sealed tube and write out all reactions. 
 
EXPERIMENT 21. 
 
 Treat a few cubic centimeters of absolute alcohol 
 with acetyl chloride and note what takes place. 
 What gas is given off? What is formed? Explain. 
 Repeat the experiment, using water instead of alcohol. 
 Explain. What conclusions would you draw regard- 
 ing the relation between water and alcohol from this 
 experiment? What use is made of acetyl chloride 
 in the laboratory ? Write out all reactions. 
 
EXPERIMENT 22. 
 
 ETHYL ACETATE. 
 
 (Acetic Ether.) 
 
 Arrange an apparatus like that used in the prep- 
 aration of ether (see Experiment 10, page 16). Into 
 the flask A put 50 grams of concentrated sulphuric 
 acid and 50 grams of absolute alcohol (93% will do). 
 Heat till the temperature reaches 130°-140° C, and 
 then add gradually through the separating-funnel a 
 mixture of equal volumes of glacial acetic acid and 
 absolute alcohol (93% will do). 
 
 Separate the crude acetic ether from the water and 
 wash with caustic soda solution ; dehydrate in the 
 usual manner with fused calcium chloride, and subject 
 to fractional distillation. 
 
 Determine color, taste, odor, boiling-point, specific 
 gravity, solubility, inflammability, etc. Is there any 
 analogy in the method of preparation of this acetic 
 ether and the method used to make ordinary ethei/? 
 What else is formed here besides acetic ether ? Save 
 specimen. Write all reactions. 
 
EXPERIMENT 23. 
 
 SAPONIFICATION. 
 
 Arrange an apparatus as shown in Fig. 8, page 
 70, text-book, using a round-bottomed 500 c.c. flask. 
 Calculate the amount of solid caustic potash neces- 
 sary to decompose 20 grams of the ethyl acetate made 
 in Experiment 22. Dissolve this amount plus'5 grams' 
 excess in 200 c.c. of water, add the 20 grams of ethyl 
 acetate, and boil together on a sand-bath until the odor 
 of ethyl acetate has disappeared. Then distil off 100 
 c.c. of the liquid and examine the distillate. What 
 does it contain ? 
 
 Let the mixture in the flask cool, and when cold 
 acidify with dilute sulphuric acid and again distil. 
 What passes over now? Prove it. Write out all 
 reactions. 
 
 Given a mixture of ethyl acetate and ethyl alcohol, 
 show how you could determine the amount of ethyl 
 acetate present. 
 
EXPERIMENT 24.i 
 
 POTASSIUM CYANIDE. 
 
 (Hood.) 
 
 100 grams of potassium ferrocyanide are dehydrated 
 by heating the powdered salt in a porcelain dish in an 
 air-bath to 110° C. until it ceases to lose weight. The 
 dehydrated salt is powdered again if necessary, and 
 then heated in an iron or copper retort provided with 
 a cover and outlet-tube (such as was used for mak- 
 ing marsh gas in Experiment 3), to a red heat with 
 a triple burner or in a Fletcher gas-furnace. A gas 
 comes off. Collect some over water and determine 
 what it is. Continue heating the retort until gas 
 ceases to come off, excluding air from the retort by 
 keeping the outlet-tube under water. Then remove 
 the outlet-tube from the water and let the retort cool. 
 Take out the contents of the retort, grind in a mortar, 
 and extract once or twice with boiling 50% alcohol. 
 Filter, and evaporate to crystallization. Determine 
 solubility and crystal form of the salt. Does it re- 
 semble potassium chloride in any way? Has it any 
 odor ? Explain. Is the salt deliquescent ? Does the 
 aqueous solution decompose ? Try it. What are the 
 products? Is the aqueous solution alkaline? Ex- 
 plain. Does an aqueous solution of the salt dissolve 
 the cyanides of mercury, gold, etc. ? Try it. What 
 
 1 Experiments 24, 26, and 27 are to be postponed until after urea 
 has been considered. 
 
use is made of this property? Does the fused salt 
 reduce metallic oxides ? Try it with some lead oxide 
 (PbO) in a test-tube. Is the salt poisonous ? Save a 
 small specimen and keep the rest for use in Experi- 
 ment 27. Write out all reactions. 
 
EXPERIMENT 25.i 
 
 (Hood.) 
 
 POTASSIUM FERRICYANIDB. 
 
 1. 
 
 Dissolve 50 grains of the crystallized potassium 
 ferrocyanide in 150 c.c. of luke warm water in a 250 
 CO. flask. Filter the solution if necessary. Calcu- 
 late the amount of bromine required to convert the 
 50 grams of ferrocyanide into ferricyanide. Weigh 
 off this amount of bromine under the hood, and add 
 it gradually (by means of a separating-funnel, hav- 
 ing its lower end drawn out into a capillary tube), 
 to the solution of ferrocyanide, shaking constantly 
 while the bromine is being added. The solution 
 is then evaporated to one-half its volume, and the' 
 ferricyanide allowed to crystallize out. The mother 
 liquor, on being evaporated down, also yields a further 
 crop of crystals. Save a specimen of the salt, and 
 determine color, taste, crystal form, solubility, etc., 
 of the potassium ferricyanide. Does the solution 
 decompose in the light ? Try it. What use is made 
 of this fact? Is it a good oxidizing agent? Try 
 it in alkaline solution with some lead oxide. Does 
 potassium ferrocyanide contain water of crystalliza- 
 tion ? Does the ferricyanide ? To a small quantity of 
 
 ' Either method may be used in making potassium ferricyanide. , 
 The second has given better results, however, in this laboratory. 
 
a saturated solution of the ferrocyanide in a test-tube 
 add an equal volume of fuming hydrochloric acid. 
 Add two or three volumes of fuming hydrochloric 
 acid to one volume of a saturated solution of the 
 ferricyanide. Explain what takes place in each case. 
 Write out all reactions. 
 
 EXPERIMENT 25. 
 POTASSIUM FERRICYANIDE. 
 
 2. 
 
 Dissolve 50 grams of crystallized potassium ferro- 
 cyanide in 300 c.c. of wafer and add 10 grams of 
 concentrated hydrochloric acid. Then run in from 
 a burette a cold filtered solution of bleaching-powder 
 until the solution no longer gives a precipitate of 
 Prussian blue with ferric chloride solution (testing 
 the solution from time to time by taking out a drop 
 or two). Neutralize any excess of hydrochloric acid 
 present with precipitated chalk, filter the solution, 
 and evaporate to crystallization. The first crop of 
 crystals will be pure ; the second may contain a small 
 quantity of calcium chloride. 
 
 Save a specimen of the salt, and examine it as 
 directed in Experiment 25, 1. 
 
EXPERIMENT 26. 
 
 POTASSIUM CYANATB. 
 
 Mix intimately 4 parts of dehydrated powdered 
 potassium ferrocyanide with 3 parts of dry powdered 
 potassium bichromate. A little of this mixture is 
 placed in a porcelain or, better, an iron dish and 
 heated (considerably below redness) until the mix- 
 ture becomes like tinder and blackens. The rest of the 
 mixture is then added, little by little, each quantity 
 being allowed to blacken before the next is added 
 (complete oxidation of the cyanide to cyanate is thus 
 effected). After cooling, the contents of the dish are 
 extracted several times with boiling alcohol (80%). 
 Filter, and cool the alcoholic solution to 0°. Filter 
 off the crystals formed, using a Witt plate and 
 suction-pump. Dry on drying-paper. Continue the 
 extraction until the black mass is exhausted. Yield, 
 42% of the ferrocyanide used. Make 30 grams of 
 the cyanate, and calculate the amounts of ferrocya- 
 nide and bichromate necessary. Save a small speci- 
 men of the salt, and put away 20 grams of the cyan- 
 ate for Experiment 48. Determine crystal form, 
 solubility, color, taste, odor, etc. Does the aqueous 
 solution decompose on standing? Try it. What 
 are the products? Add some dilute sulphuric acid 
 to a solution of the cyanate, and explain what takes 
 place. Is there any resemblance between potassium 
 
cyanate and potassium hypochlorite ? Show this by 
 the method of formation, one from cyanogen and 
 the other from chlorine and a solution of potassium 
 hydroxide. Write out all reactions. 
 
EXPERIMENT 27. 
 POTASSIUM SULPHOCYANATE. 
 
 An aqueous solution of potassium cyanide (65 parts 
 of the dry salt) is heated with flowers of sulphur (32 
 parts) until all the sulphur is dissolved. Filter the 
 solution and evaporate to cystallization. Drain off 
 the crystals and repeat the evaporation with the 
 mother liquor. Use 20 grams of the potassium cy- 
 anide made in Experiment 24 and calculate the 
 amount of sulphur necessary to form the sulphocj'a- 
 nate. 
 
 Determine properties of the salt, including color, 
 taste, odor, crystal form, solubility, melting-point, 
 etc. What takes place when the crystals are left 
 exposed to the air? Is there any analogy between 
 the formation of the cyanate (Experiment 26) and 
 the sulphocyanate ? What use is made of the sulpho- 
 cyanate in the laboratory ? Heat some of the salt in 
 a porcelain crucible and note changes in color. Let 
 cool and note any -changes. Make some mercuric 
 sulphocyanate, dry, roll into small pellets, and ignite 
 (Pharaoh's serpents). Explain. 
 
 Save a specimen of the potassium salt and write 
 out all reactions. 
 
EXPERIMENT 28. 
 
 Dissolve 5 grams of potassium sulphocyanate in 
 water, and note any change in the temperature of 
 the water. Explain. 
 
 EXPERIMENT 29. 
 AMMONIUM SULPHOCYANATE. 
 
 Mix 60 grams of alcohol (95%), 80 grams of am- 
 monia solution (sp. gr. 0.912), and 35 to 40 grams of 
 carbon bisulphide, and allow to stand in a tightly 
 stoppered bottle for one or more days until all the 
 carbon bisulphide has dissolved. The process may 
 be hastened by shaking the bottle from time to time. 
 When all the carbon bisulphide has dissolved, evapo- 
 rate the solution at a gentle heat on a steam or water 
 bath (Hood) to one-third of the original volume; 
 What goes off? Filter off any sulphur that may 
 separate out while the solution is hot. On cooling, 
 ammonium sulphocyanate crystallizes out. Filter off 
 the crystals and repeat the evaporation with the 
 mother liquor. 
 
 Determine crystal form, solubility, color, taste, 
 odor, and melting-point of the salt. 
 
 Save a specimen of the salt, and write out all 
 reactions. 
 
EXPERIMENT 30. 
 
 PHENYL ISOCYANIDB. 
 
 (See text-book, page 90.) 
 
 Dissolve a small quantity of solid caustic potash 
 in alcohol in a test-tube and add one or two drops of 
 aniline. Then add a drop of chloroform to 100 c.c. 
 of distilled water in a small flask, and shake the mix- 
 ture thoroughly. Now add a drop or two of this 
 water saturated with chloroform to the caustic potash 
 solution containing the aniline, and heat .the test-tube 
 under the hood. The odor is that of phenyl isocya- 
 nide. 
 
 This reaction is a very delicate one, and may be 
 used to detect the presence of any primary amine or 
 of chloroform. Is aniline an amine? Write the 
 reaction. What is the object of the caustic potash ? 
 
EXPERIMENT 31. 
 
 FLASHING-POINT OF KEROSENE. 
 
 Make an apparatus like the one figured on page 
 111 of the text-book, but of the following dimen- 
 sions : A is a, glass cylinder 35 m.m. wide and 175 
 m.m. high, and has a mark 60 m.m. from the bottom, 
 and another at 70 m.m. from the bottom. The kero- 
 sene is poured in up to the lower mark. The cylin- 
 der is placed in a water-bath (a beaker filled with 
 water up to the 60 m.m. mark on the cylinder), the 
 temperature of which is raised slowly (one degree in 
 two or three minutes). At each degree air is passed 
 through for five seconds so rapidly that the foam on 
 the kerosene reaches the second mark. At the same 
 time a small flame is held at the mouth of the vessel 
 A. When the vapor ignites and a bluish flame runs 
 down to the surface of the oil, note the temperature. 
 The first determination gives only approximate re- 
 sults. The kerosene is replaced by a fresh supply, 
 and the observations are begun at a temperature a 
 little below that obtained in the first determination. 
 The temperature of the kerosene and that of the 
 water-bath should differ only by one degree. Deter- 
 minations should agree to within ^°. The propor- 
 tions given for the cylinder and the directions must 
 be observed to get good results. Determine the 
 flashing-point of several specimens of kerosene, and 
 particularly of that kerosene you burn at your room. 
 See if it is above the flashing-point required by law. 
 
EXPERIMENT 32. 
 
 ALDEHYDE. 
 
 Mix equal weights (10 grams) of dry calcium for- 
 mate and dry calcium acetate. Distil from an iron 
 or copper retort. Collect some of the distillate in 
 water. What does the water contain? Prove it. 
 "Write out the reaction. 
 
 EXPERIMENT 33. 
 
 PALMITIC AND STEARIC ACIDS. 
 
 Dissolve 10 grams of solid caustic potash in 150 
 c.c. of alcohol in a 250 c.c. flask and filter. Melt 
 in a porcelain dish on a water-bath 10 grams of lard 
 and then add the alcoholic solution of caustic potash. 
 Evaporate to syrupy consistency slowly on the water- 
 bath, with constant stirring. ' Convince yourself that 
 the substance left is soap (?). 
 
 Dissolve the syrupy mass in a small quantity of 
 cold water, and filter if necessary. Add to a little 
 of this soap solution a few drops of a solution of 
 (1) calcium sulphate, (2) magnesium sulphate, and 
 (3) calcium acid carbonate, and explain what takes 
 place in each case. What is meant by the terms 
 permanent and temporary hardness of water? How 
 do you determine the hardness of a water? How 
 could you make a hard water soft? 
 
Acidify the soap solution remaining with dilute 
 sulphuric acid. A precipitate is formed. What is 
 it ? Filter off the precipitate and drain it thoroughly. 
 Recrystallize it from alcohol and determine its melt- 
 ing-point and properties. Has the substance acid 
 properties? Prove it. 
 
 Neutralize the filtrate exactly with a solution of 
 potassium carbonate or potassium hydroxide, evap- 
 orate to dryness on the water-bath, and extract with 
 absolute alcohol. Filter the alcoholic solution, and 
 evaporate off the alcohol on the water or steam bath. 
 What is the syrup which remains ? Prove it. 
 
 Save specimens of the acids and the syrup. Write 
 out all reactions after glycerol has been considered. 
 
EXPERIMENT 34. 
 
 OXALIC ACID. 
 
 (Hood.) 
 
 In a long-necked flask, of about 1-liter capacity, 
 heat gently 25 grams of cane sugar and 125 grams 
 of nitric acid (sp. gr. 1.245). Gases are evolved. 
 Explain. After the reaction is over, evaporate the 
 solution to crystallization and let cool. Filter or 
 pour off the mother liquor and add to it a smaller 
 quantity of nitric acid, heat, and again evaporate to 
 crystallization. Filter off the crystals, drain com- 
 pletely on a Witt plate, and recrystallize from dis- 
 tilled water. 
 
 Determine color, taste (poison), odor, solubility, 
 crystal form, etc., of the acid. Is it a strong acid? 
 Try it. Does it contain water of crystallization? 
 Prove it. Does it sublime when heated? Try it. 
 Is it a reducing agent? Why? Heat some of the 
 acid in a small flask under the hood with concen- 
 trated sulphuric acid and prove that both oxides of 
 carbon are set free. What does the acid yield when 
 heated with glycerol? What is potassium tetrox- 
 alate? What use is made of this salt in the labo- 
 ratory ? 
 
 Save a specimen of oxalic acid. Write out reac- 
 tions after glucose has been considered. 
 
EXPERIMENT 35. 
 
 Dissolve some oxalic acid in water and add some 
 dilute sulphuric acid (?). Now run in a little of a 
 dilute solution of potassium permanganate and note 
 what takes place. What becomes of the perman- 
 ganate and of the oxalic acid? Prove it. Write 
 out the reaction and calculate how much perman- 
 ganate would be necessary to oxidize 5 grams of 
 crystallized oxalic acid. 
 
 EXPERIMENT 36. 
 
 BASIC FERRIC SUCCINATE. 
 
 Dissolve about a gram of succinic acid in water, 
 and neutralize carefully with dilute ammonia solution. 
 Add some of this solution of ammonium succinate to 
 a neutral solution of manganese chloride and ferric 
 chloride, and boil. A precipitate is formed. What 
 is it ? Filter it off, and test the filtrate for iron and 
 for manganese, and draw your own conclusions from 
 the results. Has the filtrate an acid reaction ? Explain. 
 Write out all reactions. Compare results with those 
 obtained in Experiment 18, page 26. 
 
EXPERIMENT 37. 
 GLVCEROL. 
 
 Determine color, taste, odor, solubility, etc., of 
 glycerol. Is it hygroscopic? Can it be distilled 
 under ordinary pressure ? What is its boiling-point ? 
 Does glycerol dissolve caustic potash, lead oxide 
 (PbO), or calcium oxide ? Explain. 
 
 Put 20 c.c. of glycerol into a 250 c.c. distilling- 
 flask and distil with superheated steam. Does the 
 glycerol distil with the steam ? Prove it — see 
 Roscoe and Schorlemmer's Treatise on Chemistry, 
 Vol. III. Part II. page 350, for a method of detecting 
 glycerol. 
 
 Compare reactions of the glycerol obtained in Ex- 
 periment 33 with the ordinary glycerol. Are the 
 two identical ? ' Explain the formation of formic acid 
 by the decomposition of oxalic acid in glycerol by 
 heat. 
 
EXPERIMENT 38. 
 
 FEHLING'S SOLUTION. 
 
 Dissolve 3.5 grams of crystallized copper sulphate 
 in 60 c.c. of water to which one drop of sulphuric 
 acid has been added. Bottle and label " Copper Sul- 
 phate Solution." Take 17.5 grams Rochelle salt 
 (potassium sodium tartrate) and dissolve in 35 c.c. 
 of water. Filter and add a solution of 5 grams of 
 caustic soda in 10 c.c. of water. Make the solu- 
 tion up to 50 c.c, bottle and label "Alkaline Tar- 
 trate Solution." For use, mix equal parts of these 
 solutions. 
 
 Into a small porcelain dish put 5 c.c. of each of 
 the above solutions. Heat nearly to boiling and add 
 a few drops of a one per cent solution of glucose. 
 Note what takes place. Continue to add the glucose 
 solution drop by drop until the precipitate settles 
 and leaves the solution clear and colorless. Filter 
 off the precipitate, wash with hot water, dry, and save 
 specimen. What is this precipitate ? What becomes 
 of the glucose ? Does a solution of glucose reduce an 
 animoniacal solution of silver oxide ? Try it. What 
 conclusions do you draw from these facts as to the 
 constitution of glucose ? Write out all reactions. 
 
EXPERIMENT 40. 
 
 Dissolve 1.5 grams of cane sugar in 200 c.c. of 
 distilled water. Test a little of this solution with 
 the Fehling's solution, proceeding as directed in Ex- 
 periment 38. Does any reduction of the copper solu- 
 tion take place? Now add to the sugar solution 
 about ten drops of hydrochloric acid (sp. gr. 1.11), 
 and heat the mixture on the watej-bath to 100° 
 for half an hour. Neutralize the solution exactly 
 with a dilute solution of sodium carbonate, and again 
 test it-with Fehling's solution. Does any reduction 
 take place now ? What is the function of the hydro- 
 chloric acid? Explain. 
 
 Given a solution containing both cane sugar and 
 glucose, show how you could estimate both by means 
 of Fehling's solution. 
 
EXPERIMENT 41. 
 
 CELLULOSE. 
 
 Treat some absorbent cotton with dilute caustic 
 soda solution and warm gently; then wash with 
 water, and repeat the process, using dilute hydro- 
 chloric acid. Again wash with water, then boil 
 with alcohol once or twice, pour off the alcohol, and 
 digest with ether. Remove the ether and dry. This 
 treatment removes incrusting substances and leaves 
 a comparatively pure cellulose. Has cellulose any 
 crystalline form? Is it soluble in any of the ordi- 
 nary solvents ? Try it. Dissolve some pure cellulose 
 (Swedish filter-paper) in a small quantity of concen- 
 trated sulphuric acid ; dilute with much water, and 
 boil the solution for half an hour. Neutralize exactly 
 with an alkali and test with Fehling's solution. 
 Does any reduction take place? Explain. Write 
 out all reactions. Save a specimen of pure cellu- 
 lose. 
 
EXPERIMENT 42. 
 
 SCHWEIZER'S REAG-ENT. 
 
 Dissolve 10 grams of crystallized copper sulphate 
 in 150 to 200 c.c. of water in a 500 c.c. flask, 
 and add to the cold solution 5 c.c. of a solution of 
 ammonium chloride. Precipitate cupric hydroxide 
 from this solution by adding a slight excess of sodi- 
 um hydroxide solution. Then wash by decantation 
 with cold water, and finally on a cloth filter, until the 
 wash" water no longer gives a precipitate with barium 
 chloride solution. To 30 c.c. of ammonia solution 
 add this washed copper hydroxide as long as it will 
 dissolve, and filter the solution through glass wool. 
 This is an ammoniacal solution of copper hydroxide, 
 and is known as Schweizer's Reagent. Will it dis- 
 solve cellulose? Try it with some ordinary cotton, 
 with filter-paper, and with some pure cellulose. 
 Dilute the solutions thus obtained with water, filter 
 through glass wool (?), and acidify with dilute hydro- 
 chloric acid. What takes place ? 
 
 It is essential for the success of the above experi- 
 ment that the copper hydroxide should be washed 
 free from salts and preferably out of contact with 
 the air. 
 
 Explain the Willesden process of water-proofing 
 cotton fabrics. (See Watt's Dictionary of Chem- 
 istry, revised edition, or Thorpe's Dictionary of 
 Applied Chemistry, under Cellulose.} 
 
EXPERIMENT 43. 
 
 STARCH. 
 
 Grind in a small mortar a few grains of arrowroot 
 starch with some distilled water. Pour the creamy 
 mass thus produced into 500 c.c. of boiling distilled 
 water contained in a porcelain dish, stirring con- 
 stantly while the starch is being added. A few 
 drops of this solution is then added to a liter of 
 water and one drop of a solution of potassium iodide. 
 Does any color appear ? Add a drop or two of freshly 
 prepared (?) chlorine water and note what takes 
 place. Explain. Is the color destroyed when chlo- 
 rine water is added in excess? when alkalies are 
 added? by sulphurous acid? by hydrogen sulphide? 
 by sodium thiosulphate ? Try it with each reagent 
 with a small quantity in a test-tube. Explain and 
 write out all reactions. Does the color disappear 
 on heating? Heat some in a test-tube, and then 
 cool. Does the color reappear on cooling ? Explain. 
 From the above conduct state whether the starch- 
 iodine compound is a chemical compound or not. 
 Test the delicacy of this reaction for iodine and for 
 atarch. 
 
EXPERIMENT 44. 
 
 Study the action of bromine water on some of the 
 starch solution made in Experiment 43. Does it 
 give any color? "Add a few drops of a solution of 
 potassium bromide to some of the starch paste solu- 
 tion, dilute with water, and then add a few drops of 
 chlorine water. What takes place? Why is the 
 chlorine water added? Is the starch-bromine com- 
 pound destroyed by heat ? Try it. Is this reaction 
 between the starch and bromine as delicate as the 
 one with iodine? Could you distinguish between 
 chlorine, bromine, and iodine by means of starch 
 solution ? 
 
 EXPERIMENT 45. 
 
 Test some of the starch paste solution made in 
 Experiment 43 with Fehling's solution. Does it 
 reduce it? Add 5 c.c. of concentrated hydrochloric 
 acid to 200 c.c. of the starch paste solution, and heat 
 to boiling in a flask connected with a return con- 
 denser for an hour and a half. When cold, neu- 
 tralize with sodium carbonate solution, and examine 
 with Fehling's solution. Does it reduce the Fehl- 
 ing's solution now? Does the solution now contain 
 any starch? Test it with a solution of iodine in 
 potassium iodide solution. Explain, and write out 
 all reactions. 
 
EXPERIMENT 46. 
 DIETHYL OXALATE AND OXAMIDE. 
 
 Grind 100 grams of crystallized oxalic acid to 
 powder, and dehydrate by heating in an air-bath 
 to 100° C. Weigh the anhydrous oxalic acid, and 
 add to it an equal weight of absolute alcohol (97 % 
 will do). Boil this mixture in a flask connected 
 with a return-condenser for four hours. Then trans- 
 fer to a distilling-flask, and distil until the tem- 
 perature reaches 110° C. Add to the residue left 
 in the distilling-flask a volume of absolute alcohol 
 equal to that of the distillate, and again boil for 
 four hours in the apparatus first used. Once more 
 transfer to the distilling-flask, and distil. When 
 the temperature reaches 145° C, change the receiver, 
 increase the heat, and distil off the residue as quickly 
 as possible. From the first fractions separate the 
 ethyl formate, and, from the second, the diethyl 
 oxalate, by fractional distillation, using a Hempel 
 distilling-tube. 
 
 Determine the boiling-point, color, taste, odor, 
 specific gravity, inflammability, etc., of both sub- 
 stances, and explain their formation. 
 
 To the alcoholic solution of diethyl oxalate, result- 
 ing from the fractionation, add some concentrated 
 ammonia. What takes place? Filter off the pre- 
 cipitate, wash, and examine. Boil some with a little 
 caustic potash solution in a test-tube. Does it dis- 
 
solve? What gas comes off? What remains in 
 solution ? Prove it. 
 
 Save specimens of ethyl formate, diethyl oxalate, 
 and oxamide. Write out all reactions. 
 
 EXPERIMENT 47. 
 
 UREA FROM TTRINE. 
 
 (Hood.) 
 
 Evaporate 3 liters of fresh urine to a thick syrup 
 in a porcelain dish, first on a gas-stove, then on 
 the water-bath. When cold, add concentrated nitric 
 acid to the residue, and precipitate the urea con- 
 tained in the S5a'up in the form of the nitrate. Filter 
 off the precipitate, using a Witt plate and suction- 
 pump. Dissolve the crude nitrate in boiling water, 
 and decolorize the solution by adding a dilute solu- 
 tion of potassium permanganate, drop by drop. Then 
 evaporate the solution to crystallization, filter, and 
 continue the evaporation with the mother liquor. 
 Drain, and dry the urea nitrate, and save a small 
 specimen. 
 
 Weigh the nitrate, dissolve in water, add a slight 
 excess of powdered barium carbonate (calculated), 
 and evaporate to dryness on the water-bath. From 
 the dry residue extract the urea by boiling with 
 strong alcohol (95%), filter, and evaporate to crys- 
 
tallization. Weigh the urea obtained, and calculate 
 the percentage in the urine used. Determine crystal 
 form, melting-point, solubility, color, taste, odor,, etc. 
 Heat a little of the dry substance. What is formed ? 
 Treat a concentrated solution in a test-tube with a 
 solution of oxalic acid, and explain what takes place. 
 Add a dilute solution of urea to a dilute solution 
 of mercuric nitrate. What takes place? Add a 
 little mercuric oxide to a solution of urea, What 
 takes place? 
 
 Save a specimen of urea, and write out all re- 
 actions. 
 
EXPERIMENT 48. 
 UREA FROM AMMONIUM CyANATE. 
 
 Dissolve 20 grams of the potassium cyanate ob- 
 tained as directed in Experiment 24, page 31, in 
 water, and add to it a solution of ammonium sul- 
 phate, containing just enough ammonium sulphate 
 to change the potassium cyanate to potassium sul- 
 phate (calculated). Evaporate the solution to dry- 
 ness on the water-bath, and extract the residue with 
 boiling alcohol (99%). Filter and evaporate to 
 crystallization. Weigh the urea obtained, and see 
 how it agrees with the amount required by theory. 
 Compare the artificial urea with that obtained from 
 urine, and prove their identity by a determination 
 of melting-points and other physical and chemical 
 properties. What is formed when ammonium sul- 
 phocyanate is heated to its melting-point? 
 
 Save a specimen of the urea, and write all re- 
 actions. 
 
EXPERIMENT 50. 
 
 Dissolve 8 grams of caustic soda in 100 c.c. water, 
 and add 2 c.c. of bromine. What does this solution 
 contain ? Make a solution of both the artiiicial and 
 the natural urea, and add to some of the above 
 solution. A gas is given off. Collect some, and 
 determine what it is. What remains in solution ? 
 Urea may be determined in urine by this method. 
 Explain process, and write out reactions. 
 
 Dissolve a small quantity of sodium nitrite in 
 water, and add to it an acidified solution of urea. 
 What takes place? Explain. Reaction? 
 
EXPERIMENT 51. 
 
 ETHYLENE AND ETHYLENE BROMIDE. 
 
 (Hood.) 
 
 In a 3-liter balloon-flask put a mixture of 26 grams 
 of alcohol and 150 grams of concentrated sulphuric 
 acid. Heat to 160°-170°, and add gradually, through 
 a separating-funnel, reaching below the surface of 
 the liquid, a mixture of 1 part alcohol and 2 parts 
 concentrated sulphuric acid. Pass the gas through 
 two wash-bottles containing caustic soda solution (?). 
 Collect some of the gas over water. Determine odor, 
 taste, color, inflammability, solubility, etc. Mix 1 
 volume of the gas and 3 of oxygen in a stout cylin- 
 der, and apply a flame. What takes place? After 
 enough gas has been collected for the above experi- 
 ments, pass it into another wash-bottle containing a 
 layer of bromine, ^ inch deep, covered with water, 
 and then into a bottle containing only water. When 
 the bromine has been decolorized (explain), sep- 
 arate from the water, wash the resulting product 
 with dilute caustic soda solution, then with water, 
 separate from the water, dry with calcium chloride, 
 and distil, noting the temperature. 
 
 Determine its boiling-point, color, taste, specific 
 gravity, odor, solubility, etc. Does it solidify on 
 cooling? What is formed when it is treated in alco- 
 holic solution with granulated zinc ? Prove it. Save 
 specimen of ethylene bromide, and write out all 
 reactions. 
 
EXPERIMENT 52. 
 
 ACROLEIN. 
 
 (Hood.) 
 
 Heat in a small flask a mixtuxe of 5 grams of 
 anhydrous glycerol and 10 grams of powdered fused 
 acid potassium sulphate. Pass the gases evolved 
 through a bent tube into water contained in another 
 small flask. Note the odor. What produces it? 
 Does the aqueous solution reduce an ammoniacal 
 solution of silver oxide ? Try it. Explain. Save 
 tube containing mirror, and write out all reactions. 
 
EXPERIMENT 53. 
 
 ACETYLENE. 
 
 Screw a Bunsen burner into an iron or brass tube, 
 bent at an angle of forty-five degrees, and connected 
 with, first, an empty bottle, and then with a wash- 
 bottle containing an ammoniacal solution of silver 
 oxide,^ and then with a suction-pump. Light the 
 burner at the base, and* start the pump. Regulate 
 the air and gas so that the gas is slightly in ex- 
 cess (?), and a flame is obtained like that formed 
 when a burner "strikes back." A precipitate is 
 formed. What is it ? After sufficient has collected, 
 filter it off, wash with water, and examine. Deter- 
 mine color, solubility, etc. Does it resemble silver 
 chloride in any respect? Explain. Does it explode 
 when heated or on percussion ? Dry some carefully, 
 and try it. Write all reactions. Save silver solu- 
 tions, and put into bottle marked " Silver Residues." 
 
 1 To make ammoniacal silver oxide solution, proceed as follows : 
 Dissolve 5 grams of silver nitrate in vyater, add cautiously dilute 
 ammonia solution till the precipitated silver oxide is just dissolved. 
 An ammoniacal solution of cuprous chloride may he substituted for 
 the silver solution. 
 
EXPERIMENT 54. 
 
 Put the precipitate obtained in Experiment 58, 
 together with a little water, into a small flask pro- 
 vided with a funnel-tube and delivery-tube. Slowly 
 add, through the funnel-tube, moderately concen- 
 trated nitric acid, and warm the flask gently if 
 necessary. A gas is evolved. After the air has 
 been expelled, collect the gas over water in cylin- 
 ders, and examine. What is it ? Has it any odor ? 
 Does it burn? Does it form an explosive mixture 
 with oxygen or air? Try it. Does it unite with 
 bromine ? Try it with some bromine water. Is it 
 soluble in water? Is it lighter or heavier than air? 
 What remains in the flask from which the gas was 
 evolved ? Explain and write all reactions. Is acety- 
 lene an acid? 
 
 Save silver salts, and put into proper bottle. 
 
EXPERIMENT 65. 
 BENZENE. 
 
 Grind together intimately in a mortar 60 grams 
 of benzoic acid and 100 grams of good soda-lime. 
 Distil the mixture from an iron retort, connecting 
 the long delivery-tube of the retort with a bent 
 adapter, and surrounding the receiver with ice-water. 
 Heat the retort with a triple burner, and continue 
 the heating until liquid ceases to distil. Separate 
 the oil from the water in the distillate, wash with 
 dilute caustic soda solution (?), dry with fused cal- 
 cium chloride, as usual, and re-distil from a small 
 distilling-flask, noting the temperature at which it 
 boils. What is the substance thus obtained? 
 
 Determine its boiling-point, specific gravity (lighter 
 or heavier than water), odor, color, taste, inflamma- 
 bility, etc. Does it solidify when cooled to 0°? 
 Try it. Is it a goo(? solvent ? Try it,. What re- 
 mains in the retort in which this substance was 
 made? Prove it. Is there any analogy between 
 this method of making benzene and the method of 
 making marsh gas? Save a specimen of the ben- 
 zene, and write out all reactions. 
 
EXPERIMENT 56. 
 
 BENZENE AND TOSJaSSOEi. 
 
 Put 800 c.c. of light oil into a 1-liter distiffm^ 
 flask connected with a condenser and receiver. Dis- 
 til until the temperature reaches 125°. Put the 
 distillate into a large separating-funnel, and shake 
 it several times with small quantities of concen- 
 trated sulphuric acid. Remove the acid, wash with 
 water, and then shake once or twice with caustic 
 soda solution. Remove the soda solution, wash 
 again with water, dry with fused calcium chloride 
 in the usual manner, and subject the product to 
 fractional distillation, using a Hempel distilling-tube._ 
 Continue the fractionation until a portion is ob- 
 tained boiling at about 80°, and another at about 
 110°. Prove that the first fraction is identical with 
 the benzene obtained in Experiment 55. What is 
 the second fraction ? What is the object of the 
 shaking with sulphuric acid and the caustic soda 
 solution? Save specimens of both substances. 
 
EXPERIMENT .58.1 
 
 NITROBENZENE. 
 
 (Hood.) 
 
 A cooled mixture of 60 grams of concentrated 
 nitric acid (sp. gr. 1.42) and 80 grams of ordinary 
 concentrated sulphuric acid (sp. gr. 1.84) is slowly 
 and carefully added from a separating-funnel, drop 
 by drop, and with constant shaking, to 50 grams 
 of benzene, contained in a J-liter flask, care being 
 taken to prevent the temperature rising above 50°. 
 Gases come off. What are they ? Explain. When 
 all the acid has been added, heat the mixture on a 
 boiling-water or steam bath for half an hour, shak- 
 ing the flask constantly. After cooling, pour the 
 mixture into half a liter of cold water, and separate 
 the acid layer by means of a separating-funnel. 
 Wash the oil remaining several times with water, 
 and then with dilute soda solution, drawing off the 
 oil each time from the bottom of the funnel. Wash 
 finally with water, separate the oil from the water 
 as completely as possible, dry with calcium chloride 
 in the usual way, and subject to distillation, using 
 a plain tube as a condenser. What comes over? 
 What is the brownish residue left in the flask? 
 Determine the boiling-point, specific gravity, solu- 
 bility, color, taste, odor, etc., and yield of the nitro- 
 
 1 The vapor of nitrobenzene is poisonous, and care sliould be 
 taken not to inhale it. 
 
benzene obtained. Does it solidify on cooling ? Why 
 is the sulphuric acid added in the preparation of 
 the nitrobenzene ? 
 
 Write out all reactions, save a small specimen 
 of the substance, and use the rest in the following 
 experiments. 
 
 EXPERIMENT 59.i 
 
 DINITROBENZENE . 
 
 (Hood.) 
 1. 
 
 Add gradually 1 volume of benzene (50 grams) 
 to 2 volumes of fuming nitric acid (sp. gr. 1.52), 
 warming the mixture toward the end of the opera- 
 tion until all the benzene has gone into solution. 
 Allow the mixture to cool somewhat, then add 3.3 
 volumes of concentrated sulphuric acid, and boil for 
 some time. . After cooling, pour the mixture slowly 
 into water. Filter off the crystal mass on a Witt 
 plate, wash with water until free from acid, drain 
 completely, and recrystallize from hot alcohol. 
 
 Determine the melting-point, crystal form, solu- 
 bility, color, odor, taste, etc. What substances re- 
 main in the mother liquor ? Save a specimen of the 
 crystals, and write out all reactions. 
 
 1 Make dinitrobenzene either by this method or by the one 
 given in the experiment following. 
 
EXPERIMENT 69. 
 
 DINITROBENZIiNE. 
 
 (Hood.) 
 2. 
 
 15 grams of nitrobenzene are gradually added from 
 a separating-funnel to a mixture of 25 grams of con- 
 centrated nitric acid (sp. gv. 1.47) and 40 grams 
 of concentrated sulphuric acid (sp. gr. 1.84), con- 
 tained in a flask of 500 c.c. capacity. The flask 
 should not be cooled, but should be frequently 
 shaken during the addition of the nitrobenzene. 
 When all the nitrobenzene has been added, heat the 
 flask gently on a sand-bath until red fumes cease 
 to be given off and the reaction is complete. The 
 flask should be shaken constantly during the heat- 
 ing. After cooling, pour into a liter of water. Filter 
 off the crystals on a Witt plate, using a suction- 
 pump to drain thoroughly, wash free from acid, 
 drain, and recrystallize from hot alcohol. 
 
 Determine the melting-point, crystal form, solu- 
 bility, color, odor, taste, etc., of the crystals. What 
 substances remain in the alcoholic mother liquor? 
 Save a specimen of the crystals, and write out all 
 reactions. 
 
EXPERIMENT 60. 
 
 ANILINE. 
 
 Put 80 grams of water, 55 grams of finely divided 
 cast-iron filings,^ and 50 grams of nitrobenzene into a 
 1500 CO. round-bottomed flask connected with a 
 return-condenser. Add 10 grams of concentrated 
 hydrochloric acid through the inner tube of the con- 
 denser. Heat gently with a small flame until the reac- 
 tion begins. After the first violent reaction is over, 
 heat the flask, and continue the heating until the odor 
 of nitrobenzene has disappeared. Then add water 
 (500 c.c.) to the flask, and distil with steam. If 
 the distillate has the odor of nitrobenzene, add cone, 
 hydrochloric acid until the aniline has entirely dis- 
 solved, and extract the nitrobenzene by shaking 
 with ether. Then remove the ether, concentrate the 
 aqueous solution, and add caustic soda solution to 
 alkaline reaction, put into a separating-funnel, and 
 extract two or three times with small quantities 
 of ether. If the distillate does not smell of nitro- 
 benzene, and a little of the oil dissolves conv- 
 pletely in hydrochloric acid, simply extract it once 
 or twice with ether. Separate the ether extracts from 
 the water as completely as possible, dry with solid 
 caustic potash in the usual manner, place in a dis- 
 tilling-flask, and distil off the ether. Finally, in- 
 crease the heat, and distil the aniline. Determine 
 I Ferrum met. subt. pulv. of Schuchardt. 
 
its boiling-point, solubility, specific gravity (lighter 
 or heavier than water), color, odor, taste, etc. Has 
 the solution in water an alkaline reaction ? Try it. 
 Does aniline dissolve in dilute acids? Explain. Is 
 it affected by the light ? Does its aqueous solution 
 precipitate salts of zinc, aluminum, and iron? Try 
 it. Explain. Does aniline decompose ammonium 
 salts? Heat some with a solution of ammonium 
 chloride. 
 
 Save a small specimen of aniline, and use the rest 
 in Experiments 61 and 62. Write out all reactions. 
 (See Roscoe and Schorlemmer's Treatise on Chem- 
 istry, Vol. in. page 196, for explanation of the 
 process.) 
 
EXPERIMENT 61. 
 
 To a dilute aqueous solution of some of the aniline 
 made in Experiment 60 add a few drops of a filtered 
 solution of bleaching-powder, and note the result. 
 Explain. Very dilute solutions of aniline give but 
 a slight coloration, but a color is brought out by 
 adding a few drops of a dilute solution of ammonium 
 sulphide to the mixture. Try it, and test the deli- 
 cacy of this last reaction. 
 
 To a solution of aniline in concentrated sulphuric 
 acid add a few grains of solid potassium bichromate, 
 and warm the test-tube gently. What takes place ? 
 
 What other reactions have you already had which 
 might be used to detect the presence of aniline? 
 Write out all reactions after the aniline dyes have 
 been considered. 
 
EXPERIMENT 62. 
 DIAZOBENZENE SULPHATZ!.' 
 
 Dissolve 15 grams of the aniline obtained in Ex- 
 periment 60 in 9 to 10 times its weight of alcohol 
 (95%), and add cautiously 25 grams of concentrated 
 sulphuric acid, at first slowly, afterwards more rap- 
 idly. What is formed? Cool the mixture to 15° C, 
 add 20 grams of amyl nitrite,^ and place the flask in 
 a freezing mixture, shaking the flask constantly until 
 crystallization begins. Filter off the crystals on a 
 Witt plate, drain thoroughly by suction, wash with 
 alcohol (small quantity) and then with ether, and 
 dry in the air on filter-paper. By adding to the 
 filtrate half its volume of ether, and again placing 
 in the freezing mixture, a further quantity of the 
 salt may be obtained. 
 
 Determine color, solubility, cryst3,l form, etc., and 
 yield of the salt. Does the dry salt decompose in 
 the light? 
 
 (a) Heat some of the dry salt cautiously on plati- 
 num foil, and note what takes place. Does the salt 
 explode on percussion ? Try it. 
 
 (J) Boil some with absolute alcohol, and describe 
 what takes place. What are the products of the 
 reaction ? 
 
 (e) Boil a little of the dry salt with water. What 
 
 1 Do not breathe the vapor of amyl nitrite (?). 
 
takes place ? What are the products of the reaction ? 
 Prove it. 
 
 (c?) Dissolve the rest of the dry diazo salt in cold 
 water, and add slowly the theoretical amount of 
 potassium iodide in water. What takes place? 
 
 Distil off the oil formed with steam, separate from 
 the water in the distillate, wash with caustic soda 
 solution, dry with calcium chloride, and distil, noting 
 the temperature. What is the substance thus ob- 
 tained? Determine the color, odor, action of light, 
 solubility, boiling-point, and specific gravity (lighter 
 or heavier than water) of the substance. Save a 
 specimen. Write out all reactions. 
 
EXPERIMENT 63. 
 
 BENZENESULFHONIC ACID. 
 
 Boil gently for about thirty hours, on a sand-bath, 
 a mixture of equal volumes of benzene (100 grams) 
 and concentrated sulphuric acid (200 grams) in a 
 600 c.c. round-bottomed flask connected with a return- 
 condenser, until all the benzene is used up. What 
 is formed? When cold, pour the contents of the 
 flask gradually into three or four liters of water con- 
 tained in a large evaporating-dish. Heat the dish 
 gently on a gas-stove under the hood, and add little 
 by little, with constant stirring, powdered chalk or 
 slaked lime, until the acid is neutralized. Filter the 
 hot solution through muslin, or by the method of 
 reverse filtration (see Experiment 9), wash the resi- 
 due thoroughly with hot water, and evaporate the 
 combined filtrates to a small volume (500 c.c), filter- 
 ing off the gypsum which separates out from time to 
 time. Add carefully a saturated solution of potas- 
 sium carbonate until all the calcium is precipitated. 
 Filter, wash, dry, and save the calcium carbonate. 
 Evaporate the combined filtrates to dryness, first 
 heating it on the gas-stove, and then on the water or 
 steam bath. Powder and heat, in a small porcelain 
 dish, to 100°-120° in an air-bath. Crystallize some 
 from alcohol, save a small specimen of the crystal- 
 lized potassium salt, and determine color, crystal 
 form, etc. Use the dry salt in following experi- 
 ments, and write out aM reactions, 
 
EXPERIMENT 64. 
 
 BENZENE SULPHON CHLORIDE AND 
 SULPHONAMIDE. 
 
 (Hood.) 
 
 Grind together, in a porcelain dish, equivalent 
 quantities (20 grams) of dry potassium benzene-sul- 
 phonate and phosphorus pentachloride, and heat the 
 mixture on the water-bath until all the phosphorus 
 oxychloride has been driven off. What is formed? 
 Then add water, and wash the oil free from inor- 
 ganic salts. Separate as completely as possible from 
 the water, add 100 c.c. of concentrated ammonia solu- 
 tion, with constant stirring, and evaporate to dry- 
 ness on the steam-bath. What is formed? Recrys- 
 tallize the product from hot water, and determine 
 its melting-point, crystal form, solubility, color, taste, 
 odor, etc. Does the substance dissolve more readily 
 in ammonia solution than in water ? Explain. Write 
 out carefully all reactions, and explain each step. 
 Save specimens of the substances made. 
 
EXPERIMENT 65. 
 
 PHENYL CYANIDE (BENZONITRILE) . 
 
 Grind together intimately 40 grams of dry potas- 
 sium benzene-sulphonate and an equal weight of 
 potassium cyanide, and distil the mixture from an 
 iron or copper retort, the delivery-tube of which 
 is connected with a receiver by means of a bent 
 adapter. What substance distils? Has it a bad 
 odor (cf. Experiment 30) ? What remains in the 
 retort? Prove it. Put the oil into a 500 c.c. flask, 
 add 150 c.c. of strong caustic potash solution, con- 
 nect the flask with a return-condenser, and boil the 
 contents until the oil disappears. What is formed ? 
 What gas is given off? After cooling, acidify the 
 solution with hydrochloric acid. Filter off the pre- 
 cipitate formed, and recrystallize it from hot water. 
 Determine its melting-point and properties. What 
 is it? Write out all reactions carefully, explaining 
 each step, and save a specimen of the last substance 
 obtained. 
 
EXPERIMENT 66. 
 
 PHENOL. 
 
 Dissolve 20 grams of the dry potassium benzene- 
 sulphonate in as small a quantity of hot water as 
 possible in a silver, nickel, or iron crucible, and add 
 35 grams of solid caustic potash. Heat the crucible 
 in an oil-bath or Meyer air-bath (see Lassar Cohn, 
 page 200), or with a direct flame, to 250°-252° C, for 
 an hour, with constant stirring. The temperature 
 is taken with a thermometer placed in a thin glass 
 or copper tube closed at one end. When cold, dis- 
 solve the melted mass in a small quantity of hot 
 water, acidify with hydrochloric acid (what gas is 
 given off?), and take up the oil, which separates, 
 with ether. Separate the ether extract, dehydrate 
 it with potassium carbonate in the usual way, put 
 it into a distilling-flask, connected with a condenser 
 and receiver, and evaporate off the ether. Then 
 increase the heat and distil the oil, which should 
 be afterwards cooled in a freezing mixture, and 
 the crystals drained thoroughly on a Witt plate 
 by suction. Determine odor, taste (poison), color, 
 crystal form, boiling-point, solubility, etc. By what 
 other method have you already made this substance? 
 Make a solution in water, and perform the following 
 experiments : — 
 
 1. Add a few drops of ferric chloride solution. 
 
 2. Add ^ volume of ammonia solution, and then 
 
a few drops of a solution of bleaching-powder (1 part 
 to 20 of water). 
 
 3. Add a few drops of bromine water. 
 
 Describe what takes place in each case, and write 
 out all reactions. Save a specimen of the substance. 
 
EXPERIMENT 67. 
 
 ORTHO AND PARANITROPHBNOL. 
 
 (Hood.) 
 
 Mix 80 grams of nitric acid (sp. gr. 1.34) and 
 120 grams of water in a |-liter flask. Cool the mix- 
 ture with cold water, and add to it, gradually, and 
 with constant shaking, 40 grams of melted phenol. 
 After the mixture has stood twelve hours, pour off 
 the acid liquid from the brown oil formed, wash 
 the oil once or twice with water to free it from 
 acid, and after neutralizing the combined acid liquid 
 and wash-water with sodium carbonate, subject the 
 brown oil and wash-liquors to distillation in super- 
 heated steam. For this purpose generate the steam 
 in a copper boiler and pass it through a copper coil, 
 heated by means of a triple burner, into a round- 
 bottomed copper or glass flask of about 3 liters' capac- 
 ity, containing the oil and wash-liquors, and which 
 is heated by means of a burner (see Lassar-Cohn, 
 •page 17). What passes over with the steam? Con- 
 tinue the distillation until the distillate passes over 
 almost colorless, and the residue in the distilling- 
 flask no longer has the odor of the volatile oil. 
 Filter off the solid in the receiver, drain, and recrys- 
 tallize from alcohol. 
 
 After the distilling-flask has cooled, filter off the 
 crystals and extract the black resinojis mass repeat- 
 edly with boiling hot concentrated hydrochloric acid. 
 
Decant off the hydrochloric acid solution from the 
 tarry mass, concentrate by evaporation, and allow to 
 cool. What are the crystals .which separate? Re- 
 crystallize them 'from the same solvent, if colored. 
 Determine the crystal form, melting-point, solubility, 
 volatility, color, odor, taste, etc., and yield of both 
 substances. Have they acid properties ? Explain. 
 Write out all reactions, and save specimens of the 
 two nitro-phenols. 
 
EXPERIMENT 68. 
 
 PICRIC ACID. 
 
 (Hood.) 
 
 Heat together in a round-bottomed |-liter flask to 
 100° C. a mixture of 20 grams of phenol and 20 grams 
 of concentrated sulphuric acid until complete solu- 
 tion takes place. What is formed? Remove the 
 burner, dilute with twice the volume of water, and 
 add the solution (from a separating-funnel, and with 
 constant shaking), gradually and carefully, to 100 
 grams of nitric acid (sp. gr. 1.4). Warm the mix- 
 ture on the water-bath until the red color changes to 
 yellow, then pour into a liter of water, filter off the 
 crystals on a Witt plate, drain thoroughly, wash with 
 water, and purify by recrystallization from hot water 
 containing .1% sulphuric acid. Saturate some of the 
 crude picric acid with a solution of sodium carbonate, 
 and add to the hot filtered solution a few crystals of 
 sodium carbonate. What takes place ? Explain. 
 Determine color, odor, taste (poison), crystal form, 
 melting-point, solubility, etc., of the acid. Does the 
 solution of the acid dye silk or wool ? Doe§ the dry 
 sodium salt or the acid explode when heated or 
 struck with a hammer? Save specimens of both the 
 acid and the sodium salt, and write out all reactions. 
 
EXPERIMENT 70. 
 
 BENZOIC ACID. 
 
 (Hood.) 
 
 Boil 10 grams of benzyl chloride, (in a 500 c.c. 
 round-bottomed flask connected with a return-con- 
 denser), with a mixture of 30 grams of nitric acid 
 (sp. gr. 1.31) and 20 grams of water until com- 
 pletely decomposed (about ten hours). When the 
 odor of benzyl chloride has disappeared, and no oil 
 separates out on cooling, let the contents of the 
 flask cool, and filter off the crystals. If the crystals 
 are colored, decolorize them by boiling the aqueous 
 solution with boneblack, or by recrystallization from 
 boiling dilute nitric acid. What is this substance 
 thus obtained? By what other method have you 
 already prepared it? Determine its melting-point, 
 odor, taste, crystal form, solubility, etc. Write 
 out all reactions, and save a specimen of the acid. 
 
EXPERIMENT 71. 
 
 Put a gram of benzoic acid in a 1-liter distilling- 
 flask with 200 c.c. of water. Connect with a steam- 
 boiler and with a condenser. Heat the distilling- 
 flask and distil with steam until only 100 c.c. of 
 water remain in the flask. Neutralize the distillate 
 with ammonia solution, and evaporate to a small 
 volume; acidify with dilute sulphuric acid. What 
 takes place ? Explain. Why was ammonia solution 
 added ? 
 
 EXPERIMENT 72. 
 
 Sublime a small quantity of benzoic acid by either 
 of the methods given in the text-book, pages 285 and 
 286. Or put some into the bulb of a straight cal- 
 cium chloride tube, heat until the acid melts, and 
 then pass a slow current of air through the tube. 
 Increase the length of the tube if necessary by 
 fastening a piece of paper, rolled to the same diame- 
 ter as the tube, to it by a rubber band. Save 
 a specimen of the sublimed substance. 
 
EXPERIMENT 73. 
 
 ETHTL BENZOATE. 
 
 (Hood.) 
 
 Dissolve 20 grams of benzoic acid in 80 grams of 
 absolute alcohol, and pass a rapid current of dry 
 hydrochloric acid gas through the solution, without 
 cooling, until this gas remains unabsorbed, even 
 when the solution is cooled. The hydrochloric acid 
 gas is best generated by dropping from a separating- 
 funnel concentrated sulphuric acid into a liter 
 Erlenmeyer flask, half filled with concentrated hydro- 
 chloric acid, and drying the gas by passing it 
 through a wash-bottle containing sulphuric acid. 
 When the solution is saturated with hydrochloric 
 acid gas, connect the flask with a return-condenser, 
 and boil gently for half an hour. Pour the contents 
 of the flask into water, separate the oil from the 
 water, wash with dilute sodium carbonate solution 
 until the acid is removed, then with water. Separ 
 rate as completely as possible from the water, dry 
 with ignited potassium carbonate, decant from the 
 carbonate, and distil. 
 
 Determine boiling-point, color, specific gravity, 
 odor, taste, solubility, etc., and yield of the sub- 
 stance. What is formed when some of the substance 
 is boiled with caustic potash solution? Try it. 
 Write all reactions, and save a specimen of the 
 ester. 
 
EXPERIMENT 74. 
 
 FHTHALIC ACID. 
 
 (Hood.) 
 
 Grind to a fine powder 40 grams of naphthalene, 
 and then 80 grams of potassium chlorate, mix and 
 grind together. Add just enough water to form a 
 thick paste, so that the mass may be rolled up into 
 small balls. Dry these at ordinary temperature, and 
 then add them slowly, one by one, to 400 grams of 
 concentrated hydrochloric acid, contained in a 1-liter 
 flask. The flask should not be allowed to get hot, 
 and should be shaken constantly. What is formed ? 
 Pour off the acid solution from the pasty mass, and 
 wash with lukewarm water ouce or twice, and then 
 digest several times with alcohol ; pour off the alco- 
 hol completely, and dry at 80°. Put the purified 
 substance thus obtained into a retort with upright 
 neck, and boil with ten times its weight of nitric 
 acid (sp. gr. 1.45). The nitric acid should be added 
 a little at a time, and, after boiling awhile, more is 
 to be added, and so on. When the oil has passed 
 completely into solution distil off the nitric acid, and 
 after changing the receiver, sublime the residue in a 
 current of air. What passes over? Save a speci- 
 men of this substance, and recrystallize the rest 
 from water. Determine its melting-point, crystal 
 form, color, taste, etc. Is it an acid? Save a speci- 
 men of the acid, and write out all reactions. 
 
EXPERIMENT 75. 
 
 SALICYLIC ACID. 
 
 Boil 10 c.c. of oil of wintergreen with 100 c.c. of 
 a 20% solution of potassium hydroxide in a round- 
 bottomed flask connected with a return-condenser 
 until it has all disappeared. What is formed ? When 
 cool, acidify with hydrochloric acid. Filter off the 
 precipitated substance, recrystallize it from water, 
 and determine its melting-point, color, crystal form, 
 taste, etc. What change takes place when some of 
 the substance is carefully heated in a dry test-tube ? 
 What are the products? Prove it. Dissolve some 
 of the acid in water, and add a few drops of a solu- 
 tion of ferric chloride. What takes place? Write 
 out all reactions, and save a specimen of the acid. 
 
EXPERIMENT 76. 
 
 SALICYLIC ACID. 
 
 Dissolve 50 grams of phenol in the equivalent 
 quantity of a solution of sodium hydroxide (22 grams 
 NaOH to 100 c.c. HjO), and evaporate in a flat iron 
 dish with a direct flame, stirring constantly when the 
 mass becomes pasty, and lowering the flame. When 
 dry enough, powder, and continue the heating until all 
 the moisture is driven off. What is this substance? 
 Put the dry substance into a small tubulated retort 
 connected with a receiver, and heat the retort in an 
 oil or metal bath (or air-bath) until the temperature 
 within the retort is 100°, then pass in dry carbon 
 dioxide. Let the temperature in the retort rise 
 gradually until in the course of two hours it has 
 reached 180°. What substance distils ? Finally, let 
 the temperature rise to 220°-250°. When nothing 
 more distils at this temperature stop the operation. 
 What remains in the retort ? Dissolve the contents 
 of the retort in a little water, and acidify with hydro- 
 chloric acid. What takes place ? Filter off the 
 crystals on a Witt plate, wash with water, and 
 recrystallize from hot water, decolorizing the solu- 
 tion with boneblack if necessary. Compare the sub- 
 stance thus made with that obtained in Experiment 
 75. Are the two identical ? Prove it. Save a speci- 
 men of the acid, write out all reactions, and explain 
 the process. 
 
EXPERIMENT 77. 
 
 SALICYLIC AND PAROXVBEITZOIC ALDEHYDES. 
 
 Dissolve 50 grams of phenol in a solution of 
 sodium hydroxide (containing 100 grams of sodium 
 hydroxide to 170 grams of water) in n 1-liter round- 
 bottomed flask. Connect with a return-condenser, 
 .heat the flask in a water-bath until the temperature of 
 the bath reaches 60°, and then add gradually through 
 the inner tube of the condenser, with thorough shak- 
 ing, 75 grams of chloroform. Complete the reaction 
 by heating the contents of the flask to boiling for 
 an hour or two. Then distil off the unused chloro- 
 form with steam. Acidify the contents of the flask 
 with dilute sulphuric acid and again distil in steam. 
 What distils with the water? When drops of oil 
 cease to distil, extract the distillate with ether once 
 or twice, and shake the concentrated ethereal solution 
 in a separating funnel with a saturated solution of 
 sodiuin acid sulphite.^ What takes place ? Explain. 
 Draw off the lower layer, filter, and shake the 
 filtrate again with the ethereal solution, and again 
 filter. Continue this process as long as crystals 
 form. Wash the crystals on a Witt plate with 
 alcohol, drain completely by suction, and decom- 
 
 i.The sodium bisulphite solution should be freshly made, and is 
 best prepared by placing powdered sodium carbonate in a flask, 
 covering it with a layer of water and saturating with sulphur 
 dioxide. The commercial sodium bisulphite will not answer for 
 the purpose. 
 
pose them by warming with an excess of dilute sul- 
 phuric acid. When cold, take up the oil resulting 
 with ether, dehydrate the ethereal solution with 
 calcium chloride, put into a distilling-flask, evap- 
 orate off the ether, and finally increase the heat, and 
 distil the substance. Determine odor, color, boiling- 
 point, specific gravity, solubility, volatility, etc., of 
 the substance, and save specimens of it and its 
 sodium bisulphite compound. 
 
 Filter the contents of the flask (from which the 
 oil was distilled), while hot, through a wet filter, 
 and extract the cold filtrate with ether. Evaporate 
 off the ether, and recrystallize the product from hot 
 water. "What is it ? Determine color, crystal form, 
 melting-point, solubility, volatility, etc. Show how 
 you could distinguish between the two aldehydes by 
 the reaction with ferric chloride. Save a specimen 
 of the substance, and write out all reactions. 
 
EXPERIMENT 78. 
 
 ROSANILINIi. 
 
 Heat 1 gram of a mixture of aniline and para- 
 toluidine (2 molecules of aniline and 1 of paratolui- 
 dine) in a test-tube or small flask in an oil or sul- 
 phuric acid bath (Hood) for one and a half hours to 
 180°-200° p., together with 3 grams of mercuric chlo- 
 ride and 2 grams of aniline. What is formed? Ex- 
 tract the melted mass with alcohol, filter, and 
 evaporate to dryness on the water-bath. Does the 
 aqueous solution of the substance dye wool, silk, or 
 cotton? Try it. Save a specimen of the colored 
 solution, and write out the reaction. 
 
 EXPERIMENT 79. 
 
 Dissolve 2 or 3 grams of picric acid in hot water 
 containing a small amount of sulphuric acid. Steep 
 in this hot solution a piece of white yarn or flannel 
 and a piece of white silk. Press out the excess of 
 solution, and dry ; then do the same thing with a 
 piece of white cotton or linen cloth, and dry. Add 
 to a solution of lead' acetate some alum solution; 
 soak a piece of white cotton or linen cloth in this 
 solution, and dry partially. Then steep in the picric 
 acid solution, press out the excess of the solution, 
 and dry. Determine which of the materials are dyed 
 permanently by washing them all in hot water and dry- 
 ing. Explain, Save samples of the dyed material. 
 
EXPERIMENT 80. 
 
 INDIGO WHITE. 
 
 Dissolve some stannous chloride (tin salts) in 
 alcohol, and add enough of an alcoholic caustic soda 
 solution to dissolve the stannous acid precipitated, 
 and then a slight excess of the alkali. Add this 
 solution to some powdered indigo in a flask, and 
 warm the solution gently. Decant the clear solu- 
 tion, and pass a current of air through it, or expose 
 it to the air in a shallow dish. What takes place? 
 Explain the whole process. 
 
EXPERIMENT 81. 
 
 ANTHRAQUINONE. 
 
 Dissolve 25 grams of pure anthracene in the neces- 
 sary quantity of boiling glacial acetic acid, contained 
 in a round-bottomed flask connected with a return- 
 condenser. Filter the solution if necessary. Add 
 gradually and in small portions, through the inner 
 tube of the condenser, keeping the solution boiling, 45 
 grams of chromic acid dissolved in glacial acetic acid. 
 Continue the heating until the solution becomes in- 
 tensely green colored, then distil ofif the greater part 
 of the glacial acetic acid and save it. Pour the resi- 
 due into water. What is precipitated ? After allow- 
 ing to stand for awhile, filter, wash with water, hot 
 dilute caustic soda solution, and finally with hot 
 water. Recrystallize from hot glacial acetic acid 
 or benzene. Determine color, crystal form, melting- 
 point, solubility, etc., of the substance. Does it sub- 
 lime ? Warm one part of the substance with zinc- 
 dust (2 parts) and caustic soda solution (30 parts 
 of 50% solution). What takes place? Explain. 
 Save a specimen of the anthraquinone, and write out 
 all reactions. 
 
EXPERIMENT 82. 
 
 ALIZARIN. 
 
 (Hood.) 
 
 Heat 20 grams of anthraquinone with 60 grams of 
 concentrated sulphuric acid to 250°-260°, until, on 
 taking out a small quantity and adding it to water, 
 no anthraquinone is precipitated. What is formed? 
 Pour the mixture cautiously into a large quantity of 
 water contained in a porcelain dish, stirring the 
 water vigorously. Warm, and neutralize while hot 
 with chalk or slaked lime ; filter through muslin or 
 by the method of reverse filtration. Evaporate to 
 about half the volume, filtering if necessary. Then 
 add a saturated solution of sodium carbonate until 
 all the calcium has been precipitated. Filter and 
 evaporate to dryness, first over a free flame and then 
 on the water or steam-bath. Save a specimen of the 
 crystallized sodium salt, and convert the rest into 
 alizarin. For this purpose dissolve one part of the 
 sodium salt in as small a quantity of hot water as 
 possible in a silver or nickel dish fitted into a copper 
 bath (see Lassar-Cohn, page 200), add 5 parts of solid 
 caustic soda and 0.3 parts of potassium chlorate. 
 Heat the mixture, with constant stirring, for several 
 hours to the temperature of boiling naphthalene. Let 
 cool, and remove the melted mass by boiling with 
 water and by mechanical means. Saturate the solu- 
 tion thus obtained with dilute sulphuric acid, boil for 
 
fifteen minutes, filter while hot, and wash the pre- 
 cipitate with hot water until the sulphuric acid is 
 removed. Dry and sublime. What is this substance? 
 Determine its color, melting-point, crystal form, solu- 
 bility, volatility, etc. Does it dissolve in alkalies? 
 Explain. What is formed by heating some with ten 
 times its weight of zinc-dust in a test-tube ? Save a 
 specimen of the alizarin, and write out all reactions. 
 
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