FOR QUALITAT1YE S E MI CA L ANALS S I WAITH AN INTRODUCTORY CIHAPTER ON THE COURSE OF ANALYSIS. BY' PROFESSOR HEINRICH WILL, OF GIESSEN, GERMANY. SECOND AMERICAN, FROM THE NINTH GERMAN EDITION. EDITED BY CHARLES F. HIMES, PH.D., PROFESSOR OF NATURAL SCIENCE, DICKRINSON COTLL(IE, CARLISLE, PA. P H I L A D E L P H I A: HENRY CAREY BAIR.D, INDUSTRIAL PUBLISHER, 406 WALNUT STREET. 8TA4. Entered according to the Adt of Congress, in the year 1874, by HENRY CAREY BAIRD, in the office of the Librarian of Congress, at Washington. COLLINS, PRINTER, PIIILADELPIHIA. EDITOR'S PREFACE. THE growing opinion in favor of increased attention to the study of Natural Scienlce, as a branch of liberal education, on account of its disci2plinary value, as well as t;he practical character of the knowledge acquired, led to a modification of the curriculum of study required for the degree of Bachelor of Arts in this inStitUtion, ill SO far as to allow of the election of more extensive and practical study of Natural Science in lieu of the Latin and Greek of the Junior and Senior years. The expectation is not in this way to turn out Bachelors of Arts as chemists, etc., but simply to make this branch of a liberal education as thorough as the times seem to demand, and to afford a foundation, if desired, for subsequent scientific pursuits. In adapting a course of chemical analysis to this purpose the accompanying tables seemed peculiarly suited. Whilst compact, they are sufficiently explicit, and the summary view of the general course of qualitative analysis, and of the classification of compounds according to the properties relied upon for their detection, affords a thread, as it were, around which chemical facts may crystallize as they accumulate. For details of properties, etc., in addition to instruction in the laboratory, the student is constantly referred to some one of the manuals of analytical chemistry placed in the laboratory for this purpose. Whilst these tables seem thus well adapted to a course of college studies, their general popularity, as well as scientific character, is indicated by their extensive adoption in the German universities, and their indorsement by many of the most eminent chemists in this country, and their introduction, in part at least, into many laboratory handbooks. This second American edition, prepared from the ninth German edition, contains, besides the marks of careful revision, two new tables by the author embodying Bunselns valuable flame reactions, 4 PEDITOI9S PREFACE. and whilst nothing in the original has been omitted or changeed, new matter has been freely added by tile editor, generally placed in [ ]. Thus other methods for the separation of the alkaline earths are given, and anl additional table (XIV), which may replace parts of Tables VI and VIII with the advantage of greater simplicity and directness. The note in regard to the detection of titanic acid is inserted on account of its frequent occurrence in iron ores. The chapter on the "Course of Analysis,' from the original, is added with the hope that it may relieve any inconvenience in directingo the use of the tables. In adopting a new nomenclature for a book of this character, compactness, completeness, andc general intelligibility have been mainly consideredc Acknowledgment is nmade to many practical instructors for suggestions, especially to Professor F. A. GENTIT, of the UIniversity of Pennsylvania. CHARLES F. IEMES. DICKINSON COLLEGE, Carlisle, Pa., 1874. CONTENTS. Course of Qualitative Chemical Analysis, page 7. Table I. Preliminary Examination. -Behavior of inorganic substances at a high temperature, and with reducing agents. Table II. Preliminary Examination -Flame reactions with the gas-lamp. Table III. Preliminary Examination.- Flame reactions, (Incrustations). Table IV. Preliminary Examination. - Behavior of metallic oxides with phosphorus salt and borax. Table V. Fluxing.-Conversion of insoluble compounds into soluble. Table VI. Detection of Metallic Oxides. —Synoptic statement of their behavior with chlorhydric acid, sulphydric acid, ammonic sulphide, ammonia, and ammonic carbonate. Table VII. Detection of Metallic Oxides.-Treatment of the precipitate obtained by sulphydric acid. Table VIII. Detection of Mietallic Oxides.-Treatment of the precipitate obtained by ammonic sulphide. Table IX. and X. Detection of M][elallic Oxicles.-IX. Treatment of the precipitate obtained by ammonic carbonate, (carbonates of the alkaline earths). X. Treatment of the liquid which is not precipitated by sulphydric acid, ammonic sulphide, or ammonic carbonate, (magnesia and the alkalies). Table XI. Detcction of Acids or Halogens.-Behavior of the more importalut acids, upon heating their salts with concentrated sulphuric acid. Table XII. Detection of Acids.-Behavior of the more important aci(s with precipitants, chldrhydric and nitric acid, barie and calcic chloride. and magnesic sulplhate. Table XIII. Deltection of Acids. — Behavior of the more important acids with ferric chloride, argentic nitrate, and indigo solution. [Table XIV. Detection of Metacllic Oxides.-Second method for the treatment of the filtrate from the precipitate by H2S, to replace portions of Tables VI and VIII ] C. F. H. BUNSEN'S FLAME REA C TIONS, A METHOD OF ANALYSIS IN WHICH THE GAS-LAMP IS SUBSTITUTED FOR THE BLOWPIPES WITH A FULL LIST OF SPECIAL REACTIONS. Translated by Prof. C. F. HIMES, PH.D.. I. 5 cts. COURSE OF QUALITATIVE E CHEMICAL ANALYSIS. I. Preliminancry Examination and Solution of Solids.* —In the qualitative examination of a solid, its general nature must first of all be ascertained. This is accomplished by an examination in the dry way, which always necessarily precedes the qualitative analysis proper, in the wet way, and which includes with the carefull observation of its physical characteristics (form, color, lustre, hardness) specific gravity, etc.) that of its deportment at high temperatures, either alone, with access of air, in the flame, or in the presence of other compounds, which may effect its decomposition or solution. The preliminary examination is conducted according to Tables I to IV, and serves not only to determine the general chemical nature of the body, and the quality of the metals and metallic oxides, but may also indicate the quality of some metalloids, Table XI serves exclusively for the preliminary examination for acids, and especially for volatile acids, or such as afford volatile products of decomposition with concentrated sulphuric acid. No elucidation of these tabular statements is necessary for their application, as they explain themselves, and continued practical employment of them will impart the necessary degree of certainty to conclusions obtained by them. After the determination of the class of compounds, to which the substance under examination belongs, by the preliminary examination in the dry way, thie conversion of it into the liquid form, alone suitable for analysis in the humid way, must be considered. In many cases this operation must be preceded by'the preparation of the substance, by giving it the form best adapted to solution. If its nature permits, it must be finely pulverized, and sometimes also elutriated. This is especially indispensable with minerals, especially with silicates, as well as with a11 other compounds that are difficultly soluble, insoluble, or decomposable with difficulty. -* Substances ploaced in [ ] in the tables are of rare occurrence. 8 COURSE OF QUALITATIVE CHEMICAL ANALYSIS. It must then first be ascertained whether the substance is wholly or partially soluble, or totally insoluble in water. If partially solul)le the filtrate friom the undissolved portion will leave a clearly perceptible residue, when evaporated on clean platinum foil or in a capsule, whilst if totally insoluble no such residue will be left. The reaction of the aqueous solution, whether it be neutral, acid, or alklaline, must also be determined by test-paper. If the substance dissolves only partially in water, the constituents of the dissolved and undissolved portions must be ascertatned separately. If it is insoluble in water the effect of dilute and concentrated chlorhydric acid must be tried whllilst note is taken of any evolution of gas in the operation; carbonaltes develop CO2 with effervescence; superoxides or chromates, chlorine gas; cyanides, prussic acid; many sulph ides HS; sulphites and hyposulphites SO,, the latter with the separation of sulphur; some reguline metals (Zn, Fe, Sn, etc.) develop hydrogen gas witl HC1, or in presence of arsenic, arsenetted hydrogen; in presence of antimony, antimonettecd hydrogen. If solution in HC1 is only partial, as a rule a separation of one or mlore constituents is effected by it, and the insoluble residue must be separated from the liquid, and dissolved by further treatment (Table V). A substance (or the residue) insoluble in 1HC1, must be treated withl nitric acid or aqua regia. Many sulphides, with nitric acid, yield sulphur, which by sufficiently prolonged action collects as yellow globules, or disappears entirely, when newly formed sulphuric acid is always detected, unless the metallic oxide produced forms a compound with it insoluble in the acid. Tlius plumbic sulphide (galena) affords plumbic sulphate -with nitric acid; sulphides of tin and antimony are converted into white oxides; whilst mercuric sulphide is entirely unaffected by nitric acid, but dissolves very readily in aqua relgia. The reguline metals are almost all soluble in nitric acid, and such a metal unaffected by HNO3 must contain Au, Pt, Ir, or the rarer metals in platinum ores. Gold and platinum are soluble in aqua regia; palladium also in HNO3; tin and antimony are converted by HNO into white oxides (insoluble in excess of the acid), and are readily dissolved in aqua regia, (or in HC1 with KC10), if excess of HNO, is avoided. A substance insoluble in and undecomposable by any of the acids mentioned, even by prolonged digestion at a moderate temnperature, will be found in Table AT. anid must be rendered soluble (by fluxing), according to that table, after its general chemical COURSE OF QUALITATIVE CHEMICAL ANALYSIS. 9 nature has been ascertained by a preliminary examination in the dry way (according to Tables I to IV). II. Qualitative Examination of the Substances in Solution.In a qualitative examination of a liquid (not a solution prepared by the investigator), it is necessaiy first to ascertain — 1. Whether volatile or non-volatile ingredients are present, by evaporating a portion of the liquid on platinum foil, or in a capsule. If a fixed residuum remain it must be subjected to the processes for the preliminary examination of solids, except of course such as relate only to solution. 2. Whether its reaction with test-paper is neutral, acid, or alkaline. These tests should never be omitted, since, with care, the presence or absence of whole groups of substances can be inferred from the results. Thus it is plain that no fixed substance need be souglht for in a solution which leaves no residuum upon careful evaporation, (that is, not produced by violent ebullition). A neutral liquid as a rule can only contain salts of the alkalies or alkaline earths, since the salts of nearly all other metallic oxides have an acid reaction. The presence of free alkali, (especially in the absence of non-volatile organic compounds), excludes all oxides insoluble in alkaline liquids, and if the alkaline reaction is due to an alkaline carbonate no alkaline earth can be present. (Among the exceptions to this rule are FeO3, CuO, etc., in presence of non-volatile organic matter, as well as oxides, cyanides, sulphides, etc., soluble in potassic cyanide and alkaline sulphides.) The presence of certain metals also indicates the absence of certain acids, and vice versa; thus Ag need not be sought for in a reguline metal completely soluble in HC1, nor Au, Sn, or Sb, etc., in one soluble in HNO3. A portion of the solution of a solid, produced in any way, is employed for the detection of the metals, and another portion for the detection of the acid. A. Detection of the Metals. Table VI sets forth in a compact form the reactions of the metals with general reagents, and therefore serves as the chief guide to their detection. Whilst the course prescribed by it is easily understood with a little reflection, it is, however, absolutely necessary that the following rules be kept in view in the qualitative examination of complex compounds. 1. The Precipitation by each of the General Reagents employed 10 COURSE OF QUALITATIVE CHEMICAL ANALYSIS. must be complete. The precipitant is therefore added gradually as long as a precipitate is produced by it, or with H 2S, until the liquid smells strongly of it even after shaking. The separation of the insoluble compound formed is promoted, in almost all cases, by gently warming the liquid. Some metallic oxides (As205, MOO3, oxides of Pt, Ir, and Rh) are but slowly precipitated by HS, often only after warming the liquid, supersaturated with it, from twelve to twenty-four hours. (As205 much more rapidly however if heated to 60 ~-0 C.) 2. The precipitates which characterize the several groups must be completely freed fromt the members of the remaining groups, still in solution, by washing with water. This is accomplished, according to circumstances, either upon a filter, or also in a testtube by allowing the precipitate to subside and pouring off the clear liquid, and repeating the opeiation a number of times with fresh water. By carefully evaporating on platinum foil a portion of the filtrate from the precipitate of any group, not too small, the presence of members of the remaining -groups may at once be ascertained. When easily oxidizable sulphides insoluble in dilute acids are present, some HS solution is added to the wash water, or in case of ferric and manganic sulphides a few drops of ammonic sulphide, to plrevent oxidation when the washing is prolonged. By inattention to the two preceding conditions (complete precipitation and thorough washing), it is evident the members of the various groups may remain partially mixed with each other, and reactions may be obtained in the subsequent analytical operations which are not noticed in these tables. and which are inexplicable to the inexperienced. 3. The mineral acid eLmployed for acidulation of the liquid (if it is not already sufficiently acid) is either HICl or HNO,,, either dilute or concentrated, but not in such a quantity as to prevent the formation of insoljuble sulphides. The first is usually preferred, when the possible precipitation of AgC1, HgC1, PbCl2, etc., as indicated in Table VI, must be considered. 4. If, in following the systematic course of qualitative analysis, the presence of one or more members of the different groups is recognized and proved by the reagents suggested in the tables, the analyst (especially the beginner) must make a series of confirmatory experiments with the original substance, or its separate constituents, which may control the results already obtained. Such experiments should never be omitted by the beginner, since COURSE OF QUALITATIVE CHEMICAL ANALYSIS. 11[ it is the principal aim of analytical exercises not only to become acquainted with the simple coures of analysis, bnt to become familiar with the deportment of a body in all its relations. Only by following this important rule will the less experienced be protected from errors and deceptions. For these continually arise from ignorance of the deportment of bodies, or the non-observance of the conditions upon which the result of an experiment-the appearance of the phenomenon which we regard as the proof of the presence of a substance —rests.* The metals are further distinguished and separated according to Tables VII to X. [Or the course may be much simplified without sacrifice of accuracy, b)y proceeding according to Table XIV with the tiltrate from the H12S precipitate of Table VI, instead of treating it according to the method of that table.] C. F. TH. B. Detection of Acids or Representatives of them. The qualitative analysis of acids is quite as simple as that of metals. In almost all cases the preliminary:examiiation according to Tables I and XT, in connection with the quality of the metals previously detected, indicates in what class of acids, specially, tests are to be made. The knowledge of the deportment of a salt toward solvents, and the reaction of its aqueous solution with test-paper are especially important for,this inference. By igniting the substance alone, as well as by: heatiing it with concentrated sulphuric acid (according to Table XI), the presence of organic as well as volatile inorganic acids is ascertained. If there is reason to suspect the presence of several acids, or their salts, the circumstances must be considered, in the preliminary testing, which may possibly occasion deception, since changes may occur, or phenomena present themselves upon ignition or treatment with sulphuric acid different from those afforded by the several acids alone. Thus salts of organic acids, when mixed with nitrates or chlorates, decompose upon ignitionl without blackening, but generally with deflagration, and if sufficient organic matter is present no nitrate can then be detected after ignition, but only a carbonate, if the base is an alkali or alkaline earth. A mixture * [The translation of the chapters of Prof. Wills' Outlines, which treat of the general deportment of bodies, has not been thought necessary, since the number of text-books, more or less complete, of that description with which these tables may be used, is perhaps sufficient, and it is also advisable for some reasons to refer the student to several of these, always kept accessible in the laboratory, rather than to confine his attention to one.] C. F. H. 1 q COURSE OF QUALITATIVE CHEMICAL ANALYSIS. of a nitrate with a chloride develops, on treatment with concentratecl sulphuric acid, neither purie chlorhydric nor nitric acid, but chlorine and red nitrous vapors; in a mixture of a sulphite with a nitrate (chromate, chlorate, etc.) the sulphurous is converted into sulphuric acid; and sulphur is separated from most sulphides. That the presence of volatile organic acids in an uncombined condition may not be overlooked, the acid solution is neutralized with sodic carbonate, evaporated and ignited, when organic acids will decompose with blackening, whilst they might otherwise be volatilized undecomposed. For the detection of the moie important acids in the wet way, in substances in solution, the course in Tables XII and XIII is followed. The use of general reagents for acids in most cases is only intended to determine the presence or absence of the members of a whole group of acids. The examination for the separate acids of these groups requires in addition the employment of the special tests of the tables. If the examination for acids must take place in neutral liquids, acid solutions are neutralized with ammonia, alkaline ones with 1NO3, or also with HC1 if AgNO3 is not to be used as a precipitant. If the compound was not originally soluble in water, but was soluble in acids without visible decomposition, and the base is an alkaline earth or an earth, then the acid solution (as in case of phosphates or oxalates of the alkaline earths) cannot be tested in a neutral condition by CaC2,, since, on neutralization with ammnonia, the whole salt would be precipitated. In such cases (to which besides attention is directed in the precipitate of metallic,oxides by H,(NtH4)S), the test for the acids is made in acetic acid.solutions, (with CaC12 foi' oxalic acid, and Fe2Cl6 for phosphoric acid), or the base is first removed in the proper way, (alkaline,earths by H,SO4, heavy metals by H2S or H,(NH,)S). From the salts of organic acids, insoluble in water, the acids are removed by boiling with sodic carbonate, and the neutralized filtrate is tested with HC1. If a liquid, which contains H2S, or a soluble sulphide, is to be tested for such acids as are precipitat.ecl from acid solutions by AgNO3 but not by ferric salts (HC1,HBr,H I), the sulphur is removed by addition of ferric sulphate, and the filtrate acidified with HINO3 is tested for these acids. Compounds insoluble in water and acids are decomposed according to Tables V and XII to be tested for acids. TABLE I. PURELIINAPRY EXAMINATION. I. Behavior of Inorganic Substances and their Compounds in the Preliminary Experiments. 1. Easily volatilized when heated Compounds of ammonia and mercury, and several of arsenic, [and thallium], sulphur and its acids, water, etc. Carbon burns by ignition in ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~arbon bulrnsal (or igf~niltionu.in^ upoil, or in a dry test-tube)m the air; all organic compounds are decomposed when heated, most of them with the separation of carbon (blackening). foil, or in a dry test-tube):2|. Fusible withotMost of the salts of the alkalies and some of the alkaline earths. After intense ignition in the reducing flame, they color turmneric paper brown. 2. Fusible without volatilizing, |Some silicates, as Zeolites. Borates and alum swell up. Common salt and other salts, also many minerals, decrepitate. Of the reguline metals, antimony, and without changing color:- lead, thallium, cadmium, tellurium, bismuth, zinc, indium, and tin, fuse easily before the blowpipe; silver, copper, and gold with more difficulty; the former metals at the same time give incrustations. (See below, 8, and Table III.) 3. Deflagrate when heated ipon pon Nitrates, chlorates, perchlorates, iodates, bromates, etc. charcoal:4. Infusible, or d7ffcultlyfusible, The earths a.nd their salts; the alkaline earths and their salts. When heated they glow with white light. After ignition the earths show no alkaline reaction. Silica, and many of its compounds. Of the reguline metals, iron, nickel, cobalt, molybdenum, tungsten, platinum, iridium, palladium, and without changing color:- rhodium are infusible before the blowpipe. 5. Assume a darker color when Many metallic oxides and their salts, as: zinc oxide, yellow (glows with yellowish-green light); stannic oxide, titanic acid, niobic acid, and heated:- antimonic acid, yellow; plumbic oxide, bismuthous oxide, chromates, mercuric oxide, etc., brown. YELLOW.* VIOLET. CRIMSON. ORANGE. YELLOWISH-GREEN. GREEN. BLUE. | 6. Color the flame of a Bunsen | Soda, Potassa, Lithia, Lime.* Baryta,* Cupric oxide,** Arseni gas-lanp, or' the point of the blue or a mixture of salts Rubidia, Strontia.* Molybdic Acid, Phosphoric Acid,t Antimony, of the alkalies. ( ]es0iasBoracic Acid,t Lead, flame of the blowpipe (upon plati- of thealkalies sia. Borai Acid, Seleim Tellurous Acid, Selenium num wi, or in case of metallic |* The foloredames are distinguished with most cer- * Especialloy aftearmstesngecwithecrll hydic acid, or the Compounds of Thallium. aCpric Chloride, || Hum wire, or in case of metallic C]ompounds of Thallium, Cupric hoie* * The colored flames are distinguished with most cer- "IV addition of argentic chloride, transitory. compounds tupon charcoal):- tainty by prismatic analysis. ** Especially after the addition of some argentic chloride. Indium. t In the salts after moistening with sulphuric acid. BLUE GLASS. BLUE INFUSIBLE MASS. GREEN MASS. FLESH-RED] MASS. BROWN OR BRICK-RED MASS. GRAY MASS.. _ A__n r _ —' - A - — _-. —- -- | 7. Give, when moistened with a |Phosphates, Alumina, and many of its compounds, Zinic oid Yellowish-green. Magnesia, Baryta. Glucina, solution of cobalt, and strongly |Borates, of the Alkalies. Phosphates of the Earths, Titanic Acid, Tantalic Acid. Lime chc,coa:-Silicates, Silicic Acid and some Silicates of the Stannic oxide, Bluish-green. Strontia, heated upon charcoal: |Earths, Antimonic Acid, Muddy-green Niobic Acid, GARLIC ODOR. HEPAR.* METALLIC GRAINS WITHOUT INCRUSTATION. METALLIC GRAINS WITH INCRUSTATION. INCRUSTATIONWITHOUT S. Give, when ignited with sodic, -A__ - - - - METALLIC GRAINS carbonae, (o soicgaro ted anhsdic Most of the Comn- All compounds of sulphur Bright malleable spangles. Gray infusible powder. Metal brittle. Metal malleable. R carbonate, (or sodic carbonate and pounds of Arsenic, (selenium, tellurium) ----- ---,.... _ Antimony, Lead, Zinc, white,notvolatilein p1otassic cyanide), in the reducing without exception, Tin, white. Magnetic. Non-magnetic. I. white, volatile. I. yellow. the outer flame. ftI upon* 1 1I.~ The when moistened silver,~ Silver, white. Iron, Molybdenum,. Bismuth, Thallium, Cadmium, reddih-brown. clame, upon charcoal: The mass w hen moistened blackens silver, and with acids, develops sulphuretted (sele- Copper, red. Niokel Tungsten I. brownish-yellow. Tarnishes I. yellow. Tellurium, white. l, niuretted or telluretted) hydrogen. Gold, yellow. Cobalt Platinum, Indium Iridium. I. hite. ODOROUS GASES. METALLIC COATING. WHITE COATING. FUSED SUBLIMATE. DROPS OF WATE. GsMetallic Sulphides-of burning sulphur.' Some Arsenides - Arsenides, crystalline. Higher sulphides, brownish-yellow. All hydrates (more distinct in a 9. Give, when heated.n a glass, _Giewhn aboheatdsi an glas Selenides,-of decaying radishes. Some compounds of Mercury Antimonides, fusible. Selenides and selenium, dark red. bulb tube). tube open at botl ends, and held " Arsenides,-of garlic. (especially with sodic car- Tellurides, (Also sulphide of arsenic.) obliquely:- Some ammoniacal compounds,-of ammonia. bonate) Plumbic sulphide. Metallic fluorides (upon addition of phos- Some salts of ammonia. phorus salt). 10. In contact with zinc and VIOLET OR LILAC. BLUE. BLUE, THEN GREEN, AND DARK BROWN. BLUE, THEN MUDDY OR BROWN. GREEN. chlovhydric (or sulphuicic) acid -a-iAi., a a -io — A _ -Cr color thefluid:- Titanic Acid, Tungstic and Vanadic Acids. Molybdic Acid, Tantalio and Niobic Acids. Chr,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~hoi Ac.,id,........ TABLE II. PRELIMINARY EXAMINATION. II. Flame Reactions~ with the Bunsen Gas-lamp. C. Most of the tests described energetic than the following,;and serving for reduction on oxidizing flame. Mixtures of substances are first tested in E in Table I can be made more charcoal, or in heads of fused salts; 6. Upper reducing flame, the base of the flame to obtain in the flame mantle (for an ineasily than with the hlowpipe, C, the luminous point formed on diminishing the supply of air, stant), the coloration produced by the more volatile, unmixed by means of the non-luminous by partially closing the draught holes, by turning the collar, with that of the less volatile. flame of a Bunsen gas-lamp,pro- The test specimen is supported in the flame on a platinum 5. Reduction and oxidation in beads of fused salts. See vided with a movable collar (by wire, no thicker than a horse hair, or on a small fibre of as- Table IV. turning which the access of air bestos, fastened in a small glass tube, and held by a suitable 6. Reduction by charcoal or a metal. This is accomplished, may be regulated), and a coni- holder. The substances are tested, with very small specimens, in the detection of mercury, arsenic, phosphorus, sulphur, selel c cal chimney d, d, d, d. The in regard to:- nium, and tellurium, by heating the thoroughly dried testflame should have the form of 1. Emission of light, by holding in the hottest part of the specimen in a thin glass tubet 3 cm. long, 2 to 3 mm. wide, the annexed figure. The por- zone of fusion. The emissi 6 power is estimated as low, to the point of fusion of the glass, with a mixturE fsoi tions which serve for conduct- medium, or high, according' as the luminosity of the specimen carbonate and carbon (soot from turpentine), or with a piece ing the different reactions are falls below, equals, or exceeds that of the platinum wire in- of magnesium wire, or of sodium. Reduction of other metallic distinguished as follews: 1. troduced at the same time. compounds is effected, by first preparing a small charcoal rod, Base of theflame, A, havingthe 2. Fusibility, which is expressed on a scale of temperature by coating a splinter (as an ordinary match) three-quarters its lowest temperature; 2. Zone with the following six grades, distinguishable by the appear- length with fused crystallized sodic carbonate, and charring it c2~~L-~L 1 O effutsion, B, having the highest ance of a thin platinum wire in different portions of the flame, carefully in the flame, then placing the test-specimen, about temperature; 3. Lower oxidiz- as below red heat, incipient red heat, red heat, incipient white heat, the size of a mustard seed, mixed with a drop of fused sodic ing flame, G; 4. Upperoxidizing white heat, intense white heat. carbonate, upon the point of it,.heating it to fusion in the flame, B, the highest point of 3. Volatility, by determining the time required to volatilize lower oxidizing flame, and then passing it into the hotter porthe non-luminous flame, (serves a weighed bead (0.01 gri.) in the zone of fusion, and com- tion of the lower reducing flame opposite. The products of a,, a, a, a,, the dark nucleus, for cases of roasting and oxida- paring it with the time required to volatilize an equal weight reduction may then be further examined. a, the luminous point not in the tion that do not require exces- of sodic chloride, the volatility of which is taken as unity. normaleedd y prtall trnig he sively high temperature). 5. 4. Flame coloration, by placing the test specimen in the needed by partially turning the collar, Lower redeecing flame, D, less upper reducing flame. The coloration appears in the upper See Benson's Flame Reactions, translated by the editor of these Tables, for fuller explanation and morecomplele list of special reactions. 1 Forty of these may be made by drawing out an ordinaiy sized test-tube and cutting it with a diamond into-lengths double the size of the tubes, and dividing these over the lamp and rounding lbs closed e TAB LE III. PRELIMINARY EXAMINATION. III. Flame Reactions. (Incrustations.) The incrustations, if collected on porcelain or glass, afford with further tests decidedly characteristic reactions. 1. Metallic ilcrustations, obtained by heating a verysmall particle of the substance on an asbestos fibre in the upper reducing flame (not too large, and perfectly free from smoke), and at the same time holding a glazed porcelain'capsule, 0.1 metre in diameter, filled with water, immediately above it, on which any volatile metals present will be deposited, as a dark incrustation, surrounded by a thinner coating [often of a different tint]. On touching these with a drop of dilute nitric acid (containing 20 per cent. anhydride), on a glass rod, they are, Instantly dissolved, Slowly and with difficulty attacked, Or unaffected, Lead, cadmium, zinc, indium. Bismuth, mercury, thallium. Tellurium, selenium, arsenic, antimony. 2. Oxide incrustation, formed by holding the porcelain capsule, in the preceding experiment, at some distance from the test-specimen, in the upper oxidizing flame.* It is tested: (a) by touching it with drops of stnnous chloride, and then with caustic soda; (b) by touching with drops of argentic nitrate solution, and blowing ammonia upon it.t 3. Iodide incrustation, formed by placing the oxide incrustation on the capsule [when cold], over a wide-mouthed vessel containing fuming HI (deliquesced phosphoric triiodide), and afterward gently warming it. It is tested by the moist breath (solubility), and by ammonia blown upon it.t 4. Sulphide incrustation, obtained from the last by blowing ammonic sulphide upon it,: and then gently warming the capsule; characterized by its insolubility in water,{ color, and deportment with ammonia sulphide (blown or dropped on it). Volatile Elements Separable by Reduction as Incrustations. Metallic Incrustation Oxideedide Incrustation Metallic Incrustation Oxide Incrusttion Oxide Inruta - OxIodide Incrustation odide Incrustation Sulphide Incrustation nnd tion with nland acrsaten et n awith N3 (blown 8ulpbide Incrustatien Sniphide Incrustation and Coating, and Coating, tion with Bn1aO and with AgNOa and NH,, Cating. and Coating, wit H(NH4)|. NaHO. upon it). Tellurium, Black; White. brown White, tinged yel- Brown; breathed upon dis- Disappears perma- Black to blackish- Disappears transiTellriu, Whte.Black. Black. coating. lowish. appears transitorily. nently. brown. torily. it t~breiCherryick-red. i Black. l; with iBrown; breathed upon does Does not disap- ellow to orange,t. pearansitorypS~ ~Celeher-eium; wWhite. Brick-red. Black. White. Yellow to orange. brick-red cotig. not wholly disappear. perpears transi. Antimony, WhitBlack; wite. White. White. ack; insoluble Orange; breathed upon dis- Disappears perma- Orange. otransiAntimony, White. White. White. Orange. coating. in NHl.: appears transitorily. nently. torily. Black; with brown Lemon-yellowDisappears transiTarseic, Black; with brown White. | White. | White. Lreon-yhtel Egg-yellow; breathed upon Disappearsperma- Lemon-yellow. Disappes t iArsenic, White. White. White. brownish-red; neatly. torily. coating. disappears transitorily. nently. torily soluble in NH,. Bluish-brown; with light red Aurora-red to egg- Umber-brown; Does not disapBismuth, Blck; Yellowish-white. White. Blck. White. coating; breathed upon yellow; chestnut with coffee~~~~~~~~~~~brown coating. ~disappears transitorily, brown when dry. brown coating. pear. Geray, Black; with brown|cLlght ohrenyew ite.:White. White.! bCarmine and lemon-yellow; Disappears transi- Ilack. Does ot disapMercury, coating. breathed upon does not torily. pear. disappear. lThallium, WhiteBlack; with brown Lemon-yellow; breathed Does not disap- Black; with bluish- Does not disap|Zinc, coating. upon does not disappear. pear. gray coating. pear. Black; with brown Light ochre yel- WhitEgg-yellow to lemon-yellow; Disappears transi- Through brownish- Does not disapLead, Blc;wt rw Lgtohee- White. White. WWhite. breathed upon does not L coating. low. red to black. pear. disappear. Black; with brown Brownish-black; White. White. Coating becomes White. White. Lemon-yellow. Does n Indium, Yellowish-white. White. White. White. Yellowish-white. Yellwish-white. hite.s not disapcoating. pear. [ Wtth a small quantity of the substance the lamp should be suitably turned down so that the coating may not be spread over too much surface. By blowtng through ammonia water in a small wash bottle, with exit tube just below the cork. it may also be treated with drops of ammonia. C By an apparatus similar to that for ammonia, See t. ~ Generally insoluble ia the breath, but. possessing different degrees of solubility in drops of ater C. F. H. TABLE IV. PRELIMINARY EXAMINATION. IV. Behavior of Metallic Oxides before the Blowpipe with Sodic ammonic hydric Phosphate (Phosphorus Salt), and Borax. The bead (formed on a loop of platinum wire, or, in experiments with the reducing flame, also upon charcoal) is gradually saturated with the finely-powdered substance. In using the nonluminous gas-flame, the bead fused on a platinum wire as thick as a horse-hair, is introduced by means of a holder into the lower reducing, or into the lower oxidizingflame. (Compare Table II.) The colors of the beads frequently differ, according to their temperature, and to the quantity of the dissolved oxide. (The following abbreviations are-h. hot, c. cold, h. c. hot and cold, f. s. feebly saturated, s. s. strongly saturated.) Coao OF ~With Phosphorus Salt. With Borax. COLOR oF THE BEADS. t In the Oxidizing Flame. In the Reducing Flame.* In the Oxidizing Flame. In the Redlecing Flame. Silica gives skeleton of silica. Alumina, Silica gives skeleton of silica. Alumina. h. c. Silica, alumina, stannic oxide. h. c. h. c. Silica, alumina, stannic oxidestannic oxide.-h. c. all alkaline earths, All alkaline earths and earths (s. s. not (s. s. not clear); all alkaline earths and h. c. (s. s. not clear); all alkaline earths COLORLESSB- |and earths (s. s. not clear). Tantalic, clear), eeric, didymic, manganic, and earths, argentic oxide, tantalic, niobic, and and earths, lanthanic oxide, eerie oxide, niobic, titanic, tungstic acids, zincic, cad- stannic oxide. tellurous acid-f. s. Titanic, tunystic, and tantalic acid.-h. c. 1ianganic oxide, mlic, plumbic, bismuthous, antimonious molybdic acid, zincic, cadmic, plumbic, didymic oxide. h. Cupric oxide. oxides (f. s.); s. s. yellowish. bismuthous, and antimonious oxide. h. (f s.) Ferric oxide, eerie oxide. —h. h. Ferric oxide (iellow to red), titanic h. Ferric oxide, uranic oxide (f. s.). h. h. Tungstic acid. (h. Titanic, vanadic, YELLOW:- IVanadic acid, uzranic oxide, argentic oxide. acid. |Vanadic acid. h. Plumbic, bismuthous, and molybdic acid yellow to brown.) (to brown). -c. Nickelous oxide. and antimonious oxide (s. s.). I RED:- I h. (s. s.) Ferric oxide, eerie oxide. h. h. Ferric oxide. c. Titanic and tungstic h. Ceric, and ferric oxide. c. Nickelous c. CIzyric oxide (opaque s. s.). Nickelous oxide, chromic oxide. acid, containing iron (blood-red). oxide (reddish-brown). VIOLET:- h. c. Alanganic oxide, didymic oxide. c. Titanic acid, niobic acid (s. s.) h. c. Manganic, and didymic oxide. (Amethyst).. I Nickelous oxide containing cobalt. BLUE: — h. c. Cobaltous oxide. c. Cupric oxide. h. c. Cobaltous oxide. c. Tungstic acid, h. c. Cobaltous oxide. c. Cupric oxide. h. c. Cobaltoes oxide. niobic acid (s. s.) h. Cupric oxide, molybdic acid. c. c. Chromic oxide, uranic oxide, vanadic c. Chromic oxide, vanadic acid. h. Cup- h. c. Ferric, uranic, and chromic oxide, GREEN:- Chromic oxide, uranic oxide. h. Ferric acid, molybdic acid. ric oxide, ferric oxide, containing cobalt c. Vanadic acid. oxide containing cobalt or copper. or copper. GRAY:- c. Argentic, zincic, cadmic, plumbic, As with phosphorus salt. (dull). | | bismuthous, and antimonious oxide, tel- Also niobic acid (s. s.). lurous acid, nickelous oxide. R* eduction generally takes place more easily with phosphorus salt. In case of ferric oxide, titanic, and tungstic acid, the reduction is hastened by the addition of a very small quantity of tin to the test specimen (upon charcoal). TABLE. V FLUXING. V. Conversion of Insoluble Compounds into Soluble. If a finely pulverized compound, after being successively treated with water, dilute and concentrated chlorhydric acid, nitric acid, and aqua regia, remains undissolved, or is not decomposed or attacked by the acids in such a way as to afford decisive conclusions as to the nature of the insoluble compound, then the latter must be made soluble by fluxing, in order that its constituents may be determined in the humid way. The mode of fluxing in many cases depends upon the result of the preliminary examination; the latter should therefore be conducted with great care. If no decisive indication for the treatment of the insoluble compound according to this table be given, then it is always to be fused in form of fine powder with four parts of mixed sodic and potassic carbonates, and the fused mass treated with water, and the washed residue with chlorhydric acid. Platinum crucibles should never be employed for any substances containing arsenic or any easily reducible metal (antimony, tin, lead, bismuth, etc.). I/ a, Sulphates. b. Silicic Acid and Silicates. c. Fluorides. d. Alumina or Aluminates. e, Chromic Oxide, (Baric, strontic, and plumbic Suilphates.) (Fluorspar, etc ) (Chromic Iron.) With sodic carbonate upon char- Give with phosphorus salt skeleton With concentrated sulphuric acid When ignited with solution of co- Gives with phosphorus salt and coal they give:epar. of silica. they give fluohydric acid gas, which balt they give a blue, infusible mass. borax green beads in the outer Baric and strontic sulphates are de- The solution of the decomposable etches glass; in presence of silicic The solution is effected by fusing and inner flame. composed by fusing with 4 parts of silicates is effected by chlorhydric acid, silicic fluoride, which gives a with 3 to 4 parts of hydric potassic, The solution is effected by fusing alkaline carbonate. After treatment acid; of the undecomposable by fu- precipitate with water. or hydric sodic sulphate (or also of with hydric potassic sulphate, or with water and washing, the solution sion with 3-4 parts of alkaline car- The solution is effected by fusing carbonate), and treating with water, a mixture of potassic nitrate (or contains the acid, the residue the base bonate (or baric hydrate), treatment with 4 parts of alkaline carbonate or chlorhydric acid. [See note, Table chlorate), and alkaline carbonate. (now soluble in chlorhydric acid). with chlorhydric acid, and separating (completely by addition of silica) XIV.] Chromic iron, very finely powPlumbic sulphate gives a metallic the silicic acid by evaporation with and boilingwith water. The solu- dered, requires successive treatgrain with sodic carbonate, is black- free chlorhydric acid. Or by means tion contains the acid, the washed ment by both methods; the mass ened by ammonia sulphide, and dis- of fluohydric acid. residue the base (now soluble in resulting from the last fusion with solves in ammonia tartrate with ex- The substance must always be very chlorhydric acid). alkaline carbonate (and the oxidizcess of ammonia. Gypsum is some- finely powdered. ing agent) contains the chromium what soluble in water. as alkaline chromate, soluble in water. [See also note, Table XIV.] f. Stannic Oxide, or Anti- g, Titanic, Tungstic, Tanta- h. Chlorides (Argentic Chlo- i. Reguline metals. (Osmi- k. Carbon. rmonic Acid. lie, Niobic Acid. ride, Bromide, Iodide). Sul- ridium, or residue of platinum phides (Molybdic Sulphide, ores etc. ores.) etc.) With sodic carbonate upon. char- With phosphorus salt they give a Argentic chloride, bromide, and iodide The insoluble mass h,- metallic The insoluble mass is black (as coal they give malleable or brittle blue, violet, or (those containing iron) give with sodic carbonate a silver lustre or is black, pulverulent, and diamond, also colorless), and dismetallic grains, and are colored by blood-red bead, and with zinc and granule. The decomposition is ef- not changeable by ignition. appears when subjected to great ammonic sulphide. chlorhydric acid a coloration. fected by means of zinc and dilute The solution is effected by igniting heat in an open platinum orucible, By fusion with 3-4 parts alkaline The solution is effected by fusing sulphuric acid, or by fusing with the powder, mixed with common salt, or before the blowpipe. carbonate they become'soluble in with 6 parts of hydric potassic, or lime or alkaline carbonate, the metal in chlorine gas, or by fusing with a It deflagrates when fused with acids. They are also soluble in ex- hydric sodic sulphate (or also of car- being separated. Plumbic sulphide mixture of potassic hydrate and potasicnitrate withtheformation cess of yellow ammonic sulphide. bonate). [See note to Table XIV.] gives a metallic granule, and with potassic chlorate. of potassic carbonate, and when Moistened with chlorhydric acid nitric acid, plumbic sulphate. (See a) ignited with cupric oxide(in case of in contact with zinc, in a platinum Iolybdic sulphide gives, with phos- graphite in a stream of oxygen), capsule, they are reduced to metals. phorus salt, yellowish-green beads, gives carbonic acid. and is changed by roasting into molybdic acid, becoming blue with zinc andt chlorhydric acid..IIIIII -. ~,.-. —. P -...................................................... TABLE VI. I)ETECTION OF METALLIC OXIDES. VI. Deportment of Solutions of Metallic Oxides with Chlorhydric Acid, Sulphydric Acid, Ammonic Sulphide (Ammonia), and Ammonic Carbonate, used successively. Chlorhydric Acid, Sulphydric Acid. Ammonic Sulphide, Ammonic Carbonate, Oxides which are pre- Oxides which are Oxides which are precipitated by sulphydric Oxides which are precipitated from neutral solutions, by am- Oxides, which are neither cipitated from a neutral partially reduced in acid from their solutions, acidulated by monic seul2phide (in the presence of ammonic chloride). precipitated by sulphydric acid, or acid solutionby chlor- an acid solution chlorhydric or nitric acid, as (The solution should be supersaturated with ammonia before nor by ammonic sulphide, are hydric acid, as whilst sulphur is sulphides. the addition of the ammonic sulphide.) by ammonic carbonate, in the chlorides.* precipitated.* presence of ammonic chloride. Plumbic oxide, Ferric oxide, Soluble in Insoluble in As Sulphides.* As Oxides: As Salts:* white, crystallizable; the fluid is decolor Ammonic Sulphide. Ammonic Selphide. also precipitable by also precipitable by not precipitated: soluble in much water, ized, and containsl _ _ _ ammonia. ammonia. precipitable by sulphu- ferrous oxide. ric acid. Antimonious Mercurous N Wickelous a. Soluble in Potassa. a. In presence of white. a. Precipitable Manganic oxidee, cArgentic oxide, oxe oxidec b | oxide, oxidAlumina, colorless. Phosphoric Acid. Baryta. by Hydric-diAhrgentic oxide, odxide, [Glucina], M agnesia, crystal- Strontia. sodic Phoswhite, curdy; soluble in Permanganic acid oxide,* oxide, i,. ammonia, whence it is acid, the fluil be- Arsenious - Argentic ) F]errous || mon ia Iprecipitable by nitric o yel- oxide, o: | ox [Niobi acid] b. In the presence a).1 acid. and contains man- Arsenic acid.J low- Plumbic Ferric [ acd.of Phosphoric orl as carbonates. Magnesia, |Me'rcurous oxide, a, ox ermStannous oxide, oxide,i* oxide, e J. Insoluble in Potls- Oxalic Acid. (crystalline.) white, pulverulent; is brown. Cupric oxide, J Uranous. Not pecipiblackened by ammonia Chromic acid, Stannic oxide, yellow. Cadmic oxide, yellow oxide,: b i Co Lme, 2. Not, prcip the fluid becomes Auric oxide, ] Bismuthous oxide, Uranic oxidwhite [Thallious oxide], green,andcontains Platinic brown. oxide, J. o e saryta, Phosphate. white, curdy; more com- Ichromic oxide. oxiide, [ sof pal- Manganous o ic Potassid | pletely precipitated by| |Iridic xide, o id Soda. potas rsic aiodide.dim], eh-red. [Didymic c as phosphates or [Lithia]. |Mpotassic iodide. *rc |[Oxide of Molyrde-[Oxides of Molybde- [Oxides of os- inc oxide white oxide] * A precipitation of num], brown. miZm], oixnio oxaltes. i[Caesi ]e cur by the presenoe [Selenious acid], red [Oxides of rho- lowish. [Zirconia], [Rubidi hydrochloric acid (and also mine,itdine, sulphu di low. dium, hallios oxide], [Thoria, Ammon nitric acid) may cause a pre- ous, nitrous, hypo- [Tellurium acids], [Ruthenic n black. [Titanic acid], J E cipitate when any of the fol- chlorous, chloricbro-' black. o[xide], J, lowing are present:- mic, or iodic acid,etc., ox| * Zincic sulphide is in. Silicie acid, or generally by the soluble in acetic acid. Boracic acid, presence of any of iCobatous and nickelous Antimonic acid, the easilyrdcbeCobaltous and nickelous uArnstimonic acid, hthe easily reducible * The oxides of tungsten * The oxide of mercury sulphide are with difi- e Tehngstic acid, higher oxides which and of vanadium are is precipitated white or culty soluble in dilute farther aoxide, soluble in l-as sulpides fromprecipitated as sulphides yellowish by a little chlorhydric acid, and in fartler i i olubd inal- a slutides fr only when their solution, suphydric acid, by an acetic acid; nickelous sul- * In presence of phos- i The phosphates of The precipita- Lithiaisonly |nitricacid) aswellasmetal- |an acid. The solution of completely precipitated phide (containing ammo- ** Soluble after beinglsoluble in acetic acid; e of ammonia ltions, upon ides, cyanides allnd ferrocya u- SnS, in ammonic sulphide by sulphydric acid out of nia) with a brown color. fused with potassic hy- the calcic oxalate is also and upon heating heating by Iiyphides soluble in ammonic is precipitated by acids, dilute, and not too acid Thali and Indium drate, insoluble in acetic acid. the solution to dro-disodic phossulpbide. A precipitate of yellow, as SOS,. solutions, are nt noticed further in Aluminic posphate is boiling. phate. sulphur may also be formed *** The platinum me-lthes6 tables, (traces of soluble in potassa. in soluble polysnlphides and tals are precipitated with them only occur, and they hyposulphites. difficulty by H2S. aree asily detected by the spoetfoscope). _~1~11 -1 _ _ __ _____ ____~~~~.. TABLE VII. DETECTION OF METALLIC QXIDES, VII. Treatment of the Precipitate formed by Sulphydric Acid in Warm Acid Solution. A portion of the washed precipitate is digested with ammonic sulphide (with potassic sulphide if copper, be present), filtered, if there be a residuum, and to the liquid, dilute sulphuric acid is added. (If the solution be partial, the remaining portion of the precipitate is subjected to the same treatment; if it be complete this is not necessary.) If the precipitate formed by dilute sulphuric acid be not white, milky (of sulphur alone), but flocculent, and more or less colored, it (or the original precipitate, if it is entirely soluble in ammonia sulphide) is treated according to A.-The precipitate insoluble in ammonic sulphide is examined according to B. A. The Portion soluble in Ammonic Sulphide. The yellow or orange-red precipitate (containing arsenious, stannic, or antimonious sulphide, or a mixture of them) is gently warmed The brown or brownish-black precipitate with a concentrated solution of ammonic carbonate, and the solution filtered.* may contain: (a.) Solution contains: (b.) Residue contains: Cupric sulphide (traces), Arsenious (a little stannic) sulphide. Antimonious sulphide, stannic sulphide. Platinic sulphide, i To be detected, Add some I-2S solution, supersaturate with chlorhydric Dissolve the sulphide in chlorhydric acid and (a little) potassic chlorate, Iridium sulphides, if their preacid, and warm; dissolve the separated sulphide in fuming and test the solution for:- Auric sulphide, sence is susnitric acid, or in chorydric acid and ( little) potassic chlo- 1. Antimony, by bringing several drops in contact with a fragment of Tellurium sulphides, pected, by the nitric acid, or in chlorhydric acid and (a little) potassic chlo- zinc on platinum foil (antimony produces a deep b~lak wtafnen of by the || zinc on platinum foil (antimony produces a deep black stain); or by formarate. When arsenic is present, a precipitate is formed in the tion of SbH1 (antimony spots do not dissolve in sodio hypochlorite, and are olybdenun sulphides, ethods of the solution (after it has been supersaturated with ammonia, and blackened by ammonio-nitrate of silver, after oxidation by dilute nitric Tungstic sulphides, preliminary filtered from any separated stannic oxide), by a mixture of acid cautiously evaporated). Vanadium sulphides, examination. 2. Tin, by warming the solution with zinc, dissolving the precipitated magnesic sulphate, ammonic chloride, and ammonia. Traces black metallic powder, washed off of the undissolved zinc, in warm chlorof arsenic are detected by converting into AsH3 in Marsh's hydric acid, and adding mercuric chloride to the solution. (A white or gray apparatus (arsenic spots disappear in sodic hypochlorite). precipitate indicates tin.) * By treatment of the sulphides with concentrated chlorhydric acid, with aid of heat, arsenious sulphide remains undissolved (to be farther tested according to (a)), whilst the solution may be tested for antimony and tin (according to (b)). The separation is more complete by digesting the solution oY- the sulphides in potassic sulphide with excess of sulphurous acid, finally expelling the latter by boiling; the arsenic alone will remain in solution, as an arsenite. B. The Portion insoluble in Ammonic Sulphide, The well-washed precipitate is treated by aid of heat, with concentrated nitric acid (free from chlorine). It is either fully dissolved, or there is a residuce. If the original fluid (before precipitation by sulphydric acid), was acidulated with chlorhydric acid, then this precipitate can contain no argentic sulphide, and no sulphide of mercury arising from Residue may consist of: Solution may contain: Plumbic, argentic, bismuthous, cupric, cadmic, [and palladious] oxide. Dilute sulphuric acid is cadded to it. Yellow or gray, floe- Black, flocculent.- White, pulverulent, Precipitate. Chlorhydric acid is added to the filtrate:culent, or balled up, The solution in aqua soluble in almmonic Plumbic sul -__ often inclosing metal- regia, somewhat eva- tartrate with excess of phate. Precipit te. The filtrate is sspersaturated with ammnonia:lia sulphides. porated, is precipitat- ammonia. Soluble in Argentic chlo- P-ectate. e itratemay contain.Precipitate. The filtrate may contain:aed by stannous chlo- ammonia tar- ride. ride. Bismuthous oxide. trate with ex- Soluble'inam- Its solution in a Cupric oxide. Cadmic oxide. [Palladious oxide.] If sulphide of mercury is found, the original fluid is tested forniac thence it retdb little chlorhydric The blue ammoniacal The colorless am- The original(bow mercuric and mecuros oxide. Chlohydric acid is added to thefluid. i precipitatenitriacid acid acquires aacal solution is (sfters prcipitated whitish turbidity ulation), precipitated precipitated yellow black by po ~eci~itnde. by potassic Precipitate. Filtrate. with water, a black reddish-brown by po- by sulphydric acid. iodide. Mercurous chloride Mercuric chloride. with stannous oxide tassic ferrocyanide. Becomes black with ammonia or Excess of stannous chloride in potassa. potassa. precipitates metallic mercury; re- For the recognition of cadmic oxide in presence of cupric oxide, potassic cyanide is added to the blue ammoniacal cognized by rubbing on clean cop- solution, until the color vanishes; then only cadmium is precipitated by sulphydric acid. Or the precipitated per. sulphides are heated to boiling with dilute sulphuric acid, in which case only the cadmium is dissolved..~~~~~~~~ TABLE VIII. DETECTION OF METALLIC OXIDES. VIII. Treatment of the Precipitate formed by Ammonic Silphide, or Ammonia, in presence of Ammonic Chloride. [For a different treatment compare Table XIV., and notes. C. F. H.] If nickel is present the filtrate, from the ammonic sulphide precipitate, is brown. After being washed, the precipitate is treated upon the filter with warm dilute chlorhydric acid, the resulting solution is heated with (not too much) nitric acid or potassic chlorate, in order to remove the sulphydric acid and to convert any ferrous salt that may be present into a ferric salt. If, upon dissolving the ammonic sulphide precipitate in chlorhydric acid, a black residue remain (CoS or NiS), it is first to be tested before the blowpipe for cobalt, then dissolved in aqua regia, and the solution added to the chlorhydric acid solution. (If but one base is to be sought for, the original fluid may also be employed for testing according to this table. It serves also for determining, when iron is present, whether it appears as ferrous or ferric oxide.) The Solution is strongly supersaturated with Caustio Potassa, the Precipitate, if one remain, gently digested, and filtered. The Fluid or Filtrate may contain:*- The Precipitate may contain:-. Chromic oxide, zincic oxide, alumina, aluminic phosphate, Cobaltous, nickelous, mangenous, ferric, and uranic oxide; baric, strontic, calcic, and magnesic phosphate; calcic oxalate; [glucina]. calcic fluoride; [all rare earths insoluble in potassa]. (Also alumina and chromic oxide with magnesia and zincic oxide; zinoic oxide with ferric oxide.*.) Boil the (green) potassa solution for some time. zincic oxide with ferric oxide.*) Dissolve the washed precipitate in a little chlorhydric acid, add ammonia chloride and ammonia. |irecipitate: Filtrate may contain:- Filtrate may contain:* — Precipitate may contain:Chromic oxide. Zincic oxide, Cobaltous, nickelous, and manganous oxide, (zincic oxide, erric and uranic oxide; bari, strontic, calci, and magnesi (Also glucina and zincic Alumina, magnesia.) phosphate; calcic oxalate; calcic fluoride; [all rare earths;] oxide.) Aluminic phosphate,* (also alumina, chromic and manganie oxide). Precipitate the fluid, slightly acidulated with acetic acid, (also alumina, chromic and manganic oxide) Test by the blowpipe. [Glucina]. with sulphydri acid, by aid of heat. igest the precipitate with concentrated solution of ammoni Separate the filtrate into two portions and add: — ~~~~Precipitate:. Filtrate: | Residue may contain:- Solution may cn Sulphydric acid. saturating with chlorhydric Cobaltous sulphide. Manganous oxide and magnesic phosphate; calcic oxalate, ai Nickelous sulphide, (Magnesia). (and fluoride). Uranic oxide Ammniacid), c e (Zincic sulphide). Evaporate to dryness, and Dissolve in a little chlorhydric acid, and Cerous oxide, ll Ammonic carbonzate. |testtheresiduebyfusingwithtest the solution in separate portions Lanthanic oxide: Test for cobalt by the blow- for:-D l Precipitate P recspitate pipe, or by potassic nitrite; sodic carbonate and nitre upon Didymic oxide, Zincic sulphide. Alumina, aluminiP phosphate, for nickel by mixing the liquid Platinum foil. A bluish-green a. Ferric oxide (with potassic ferrocya- Yttria, Zncc sulphde. Alumin [ a heatedwith excess of potassiclmass indicates manganese. nide). (it soli Thoria, _ - I aThe separation of zincie oe from ferric oxide by means of ri chloride unoti clticos pro-acor rin: aati cypotasa is not complete, on which accounr test in the presence of the duced heat to boiling precipitate theibrown precipitate (hromic and zincic oxide cannot est by the alkaline latter, some zncc xd e a lways goes over into the almonxiacal fluid, g m. Glucina is solublesoluble in potassaide. are - zini oxide, as well as from magous nickelous and cobalto test with phosphatei ox aate santdri hypochworith nitric aci, aaotdei n~acetateos thien M ag n o o esia)hlr. (ae When uranic o xide is chrsoltioxwid r cont m carbonate.) is td. aMacitanesia (add sodic acetate, then foe pir-tpresent, the solution, afwi ammoia or ammoisulphide with those oxides as a gelatinous coxidonte froinm ferric ox ide by means of rio chloride until reddish color is pro- t supersattion withe). compound insoluble in Evap oialin itso in poedtoassa, d manganicsideasoe ai thle mnaeselorhydr cid, my Croic ao id, ves a with NHCl or by dissolving repeatedly in HC and precipitating easily pass into the ammonia precipitduced, t to boiling, precipitate the brown precipitate with oxide, hromic and zipresenci of which in the residuboth be presentolubl in the alkaline latter some incic oxi the cold, or immediately on gent warming, cipitate insoluble in acetic acid. easolution atly the same time, as in that case,(by they fgreeor the compound and is found as zincice suphide. The separation offerric oxide from Znf rom magnesia, zin potatessa. Chromic and ferric oxides are s- zincic oxide, as well as from manganous, nickelous, and cobalts test with soic phosphate. fectly effected by fusion with potassic carbonate and nitrate or by trite. carboxide, cessivelyng the precipitated accordingc hypochlorite. For their relative detection g. Phlorine (with the original substance.) itl sl of a small quantity of alumina gnesin in connection with alumina or theain, by boiling the sightl acid solution, after adding sdi acetate chsupersatuomic raoxide, a part of the magnesia is aliquiways precipitated by allm- the iron being precipitated, if present as faciderric oxide. solution ferr o de ammonia or bammonte.ic suTphide wtection of phosphe oxides as ia gelatinous containing mangaous xide, ammnic chloride, and ammoni, de- or with ammonie moy etate. i on (Yel-i with alumina is effected by ammonia molybdate. loish, flocculent, or gelatino s.) l heaposits, when exposed to air, mangadic oxide, so that manganese may f. Oxalic acid (calaic oxalate is precips- employed when there is heating the precipitate with sodic hypocheorite. For the detection g. Fuorine i ri wf a small quantity of alumina (th theuoriig inal serubstoxidea nc. precipitate by ammonic sulpbide is boiled mith potassa, the filtrate * Also ferric phosphate is, when cold, precipisupersaturated with HC. and the clear liquid neutralized by am- tated from the chiorbydric acid solution (mademonic carbonals. The detection of phosphoric acid in connection as neutral as possible) by sodic acetate. (Y lwith aluminad is effected by ammonic molybdate. lowish, tlocculent, or gelatinous.) i TABLES IX. AND X. DETECTION OF METALLIC OXIDES. IX. Precipitate by Ammonic Carbonate in presence of Ammonic Chloride and Free Ammonia. Baric, Strontic, Calcic Carbonate, or a mixture of them. The washed precipitate is dissolved upon the filter in a little chlorhydric acid [or in acetic acid if the Second Method below is to be used], and the solution divided into three portions. If only one base is to be sought the original solution can also be employed for this purpose. I, Portion. II. Portion, III, Portion. [Secolld Method, c. r. H.] RemarksI Add Precipitate with excess a. When baryta is present.-Eva- Dissolvethe precipitate by ammoniccarbonate If no metallic oxide precipitable by sulphydric calcic sulphate. of dilute sulphuric acid,* polate to dryness, digest the residue in dilute acetic acid, and add to the solution acid or ammonic sulphide be present, the original upersaturate the filtrate with alcohol, and ignite the filtrate. neutralpotassic chromate. solution may also be used for these tests (exImmediate precipitation: with ammonia and add Crimsso flame:- Precipitate (yellow). Baryta. cept of Portion III. a), magnesia or alkalies not with__ammonia_, a-__d add. Supersaturate the filtrate with ammonia, and interfering with the result. l potassic [or ammonic - add ammonic carbonate, wash the precipitate Baryta is also recognized with certainty in Baryta. oxalate. rontia. (strontia and lime), dissolve in a little acetic presence of strontia and lime, by a solution of Turbidity after some time: Precipitate insoluble in b. When baryta is absent.-Strontia acid, and to a portion of the solution add, not strontic sulphate, which causes a white precipiis also recognized with certainty, since too little, calcic sulphate.* tate, appearing only after a time with traces of acetic acid. the solution in chlorhydric acid, by Turbidity after some time. Strontia. baryta. Separation of baryt.a from strontia is 0 Strontia. l |1addition of solution of strontic sul- | Precipitate the strontia from another portion effected by hydrofluosilicic acid, with addition Fluid remains clear: phate, does not become turbid, even by dilute sulphuric acid, filter, supersaturate of alcohol, in which baric silicofluoride is quite Lime. after a long time, whilst with calcic the filtrate (or acetic acid solution, if strontie'insoluble. The alkaline earths may also be |i_ _ _ _ sulphate it gives a precipitate in a be, absent) with ammonia, and add ammoni( letected by the spectroscope. short time. oxalate. * In the absence of baryta Precipitate (insoluble in acetic acid). Lime. and strontia precipitation by sulphuric acid is unnecessary. * Or add not too little dilute solution of potassic sulphate (1 part by weight to 200 by measute of water). Turbidity after some time, Strontia. Add to the liquid dilute sulphuric acid,\ lter, supersaturate the filtrate (or liquid if no turbidity was produced by potassic sulphate) with ammonzia, and add aramonic oxalate. Precipitate (inSoluble in acetic acid), Lime. X. Fluid which is Precipitated neither by Sulphydric Acid, Animonic Sulphide, nor Ammonic Carbonate. It may contain: —Magnesia, Potassa, Soda, Lithia, Bubidia, Cwesia, Ammonia, or a mixture of these bases. Evaporate a portion (not too small) of the fluid upon platinum foil; if after ignition there is no residuum, neither magnesia nor alkalies need be considered, but ammonia should be. Test for Ammonia. Test for Magnesia. Test for Potassa, Soda, Lithia, Rubidia, and OCesia. Warm the original substance or its Add sodic phosphate (and free ammo- a. fWhen magnesia is absent. Evaporate fluid X. (to which no sodic phosphate has been added) to dryness, solution (not the fluid, X.) with calcic niaif not already present) to u portion ignite gently (to remove the ammonic salts), test the residue before the blowpipe upon platinum wire, or by hydrate. of the fluid X. (or to the original so- overflowing with alcohol and igniting. A violet flame indicates presence of potassa [rubidia and cesia] alone, The presence of lution if it contain no metallic oxides a crimson of lithia, a yellow of soda, or a mizture of soda with potassa or lithia.* In the latter case, test the l Amnsonia or alkaline earths). residue for potassa [rubidia and cmesia], by tartaric arcid, or platinic chloride and alcohol in not too dilute The presence of magnesia is mani- solution; for lithia, by boiling with sodic carbonate'and phosphate, whereby a salt forms, soluble with diffiis recognized by the odor, as well as fested by a crystalline precipitate, culty; or by a mixture of anhydrous ether and alcohol, in which lithic chloride dissolves, recognizable by by the white cloud which arises when which forms slowly when only traces the crimson flame. a glass rod moistened with chlor- of magnesia are present. (If the b. When magnesia ispresent. Evaporate to dryness, ignite the residue gently, to remove ammonia salts, hydric acid is brought near. separation of the alkaline earths by and warm with water. Add to the solution baryta-water, or milk of lime to alkaline reaction, boil, and filter. Slight traces may be detected by ammonia and ammonic carbonate did Remove the excess of baryta or lime by ammonia and ammonic carbonate (or of baryta by dilute sulphuric condensing the vapor, developed by not take place at a boiling heat, sodic acid), and evaporate the filtrate to dryness. If there is a residue, proceed with it as in a. Or test for alkalies calcic hydrate, in a test-tube, and phosphate will always give a small, )y the spectroscope. adding to it an alkaline solution of flocculent precipitate of a phosphate mercuric iodide in potassic iodide; of an alkaline earth.) * Potassa [rubidia, carsia], soda, and lithia can also be distinguished by the effect of transmission through colored media upon ammonia producing a brownish-red their colored flames. If the substance to be tested (best as a sulphate) is held in the loop of a platinum wire in the outer ent precipite. velope of a (pure blue) gas or alcohol flame, if soda be present the whole upper part of the flame will be colored yellow. If flat glass bottle with parallel sides containing a solution of indigo is now brought between the eye and the flame, the color of the flame will entirely disappear, in case only boda be present; a simple change, however, to violet or red indicates potassa, or lithia. If the flame is then observed through deeply colored cobalt glass, the violet color remains by presence of potlass [rubidia and casia]; the last two as well as the alkalies in general are detected with most certainty by means of the spectroscope. [Traces of sodium are most readily detected, and distinguished from potassium, when both are in form of chlorides (free from organic acids and other bases), by placing a drop of the concentrated aqueous solution on a slip of glass, adding a drop of PtC14, and gently evaporating, when potassic platinic chloride will crystallize in octahedra, and the sodic salt in orange needles, best distinguishable by a magnifier.] TABLE XI. DETECTION OF ACIDS. PRELIMINARY EXAMINATION. XI. Behavior of the more important Acids, or of the Halogens, upon Heating their Compounds with Concentrated Sulphuric Acid. A quantity of the dry compound, about as much as will lie upon the point of a small knife, is placed in a test-tube and 3-4 times its volume of concentrated sulphuric acid poured upon it, then heated, but not to the boiling point of sulphuric acid. With all volatile acids, or those which suffer decomposition by sulphuric acid at a high temperature, the evolution of vapor or gas may be observed, from the properties of which, in most cases, the nature of the acid or of the halogen may be inferred.* Non-Volatile Acids. Acids Volatile, or Decomposable with Evolution of Volatile Products, I No gas or vaipor is evovTed. l~The vapors or gases evolved are colorless. N A~o gas or vapor is evolved. l A colored gas is evolved. The compound does not blackenTh e com pound does not blacken The copound does not blacken by Th comd o by I~ignition. lignition. ~T'he compound does not blacken by |The compound is decomposed by ignition. ignition. Mostly without separation of carbon. With separation of carbon. Silicic Acid, recognizable by Iodohydric Acid, the violet Carbonic Acid, odorless, ren- Oxalic Acid, develops carbonic a. Acids not volatile per se. means of phosphorus salt before vapor colors starch blue. ders lime-water turbid. acid i crbonic oxide: the lime All componds of these acids are decomthe blowpipe. slt is insoluble in cetic nid. posed by concentrated sulphuric acid, Boracic Acid, after addition of Bromhydric Acid, the brown Cyanic Acid, excites tears, and blacening thereby and developing O, sulphuric acid, it colors the alcohol vapor colors starch a fiery yellow renders lime-water turbid. ormic Acid, evolves only co- O, and Sflame green. iphurousAcid iecognbl bustible carbonic oxide gas. Tartaric Acid, the acid potassic BoiAi.Lktepe Sulphurous Acid, recognizable salt is soluble with difficulty; the Phosphoric Acid, precipitable Bromic Acid. Like the pre- by its odor; colors dissolved potas- Cyanhydric Acid, like the re lime salt is soluble in caustic poin neutral solution by magnesic sul- ceding; the salt deflagrates upon sic chromate green. ceding, but evolves with dilute chlor- tassa. phate, ammonic chloride, and am- charcoal. hydric acid cyanhydric acid. monia; in acid solution by ferric Sulphydric Acid, recognizable Racemic Acid; the lime salt chloride and sodic acetate. Chloric Acid, the greenish-yel- by its odor; colors lead-paper Ferrocyanhydric Acid, like is insoluble in ammonic chloride. sodic carbonate upon charcoal ously, and precipitates a solution of | Ferricyanhydric Acid, lik e ie oiling. arsenical odor. Hypochlorous Acid, yellow- silver on a glass rod curdy; this precedipng; the soluble compound is Mtialic Acid, is not precipitated Sulphuric Acid, the compound ish-green chlorine gas, like the pre- precipitate dissolves in ammonia, precipitated blue by feous saltsher cold or warm. gives hepar when heated with sodicceding discoloring solution of indigo. NitChromic Acid, evolves oxygen, Lactic Acid, dissolves reaily carbonate upon charcoal. cd, nearly colorless and the luid becomes brown or in ether. he lie salt is eaily elenic cid, like the preced- Nitrous Acid, red fumes; even fumes, which become red upon addi- green. Gives a green bead with the zinc difficultly, soluble in wateri Seleni Acidlikethepreced-tion of ferrous sulphate or copper iphosphorius salt. Tannic Acid, gives a white, ing. The baryta salt is decomposed with dilute sulphuric or nitric acid. filings. by boiling with concentrated chlor-li Hyposulphurous Acid. I viscous precipitate, with gelatine a hydric acid. Nitric Acid, nearly colorless Fluohydric Acid, copiously Trithionic I blueblack with ferric salts. Tungstic Acid, recognizable by acid fumes, which are red if chlorine fuming corrosive gas. A glass sur- Tetrathionic * Gallic Acid, not precipitable by the blowpipe; becomes blue with be present; deeper red if ferrous fce coated with wax and traced is gelatie; ferric salts produce a zinc and chlorydric acid. sulphate or organic substances be endered dim in the traced places by Pentathionic J black precipitate. zinclandic Acid, c c c.sulphate or organic substances be the gas. Fluorides develop in a Uric Acid, gives a red color Molybdic Acid, recognizable added. glass tube with sulphuric acid, in with ammoniut, after eviporn by the blowpipe; becomes first blue, addition to HF, also silicic fluoride These acids, of which only the ypo- with nitric a fter evaporationid. theny brown with zinc and chor- ives a preipitte of ulphuronus (triosulphuric) is of friequent. hydric acid. gas, which gives a precipitate of occurrence, evolve with sulphuric acid,. cids voltileper e. silica on a glass rod moistened with sulphurous acid, with separation of sulTitanic Acid, recognizable by water. Siliofluorides behave simi- phur. Their salts of the alkalies give he- The compound does not blacken,or but the blowpipe; becomes violet with larly they also evolve silicic i po- ar when heated in a glass tube. slightly, with sulphuric acid. zinc and chlorhydric acid. ride in a platinum crucible with sul Acetic Acid, gives, with sulphuric acid and alcohol, acetic ether Iodic Acid. The violet vapors phuric acid., acetic ether. of iodine form on addition of ferrous F Their neutral sulphate. The coipound deagrates Benzoic Acid, I salts are preciupon oharcoal. en i Acid, pitated a light Succitnic A ci, r ecobrown by ferric chlorite. If by the above methods a hydracid is found, the dry compound contains the corresponding halogen combined with a metal. In a mixture of salts other reactions often take place; thus a metallic chloride along with a nitrate develops chlorine and red vapors; along with a chromate brownish-red fumes of chlorchromic acid, etc. The chlorides of mercury are hardly decomposed by sulphuric acid. Metallic sulphides with concentrated sulphuric acid frequently develop sulphurous acid. larly; they also evolve silicic i TABLE XII. DETECTION OFACIDS. XI. Behavior of the more important Acids towards Precipitants. A. Detection of Acids in soluble ccmlpounds. —The aqueous solution is neutral, acid, or alkaline, to be determined by test paper. If the acid is to be sought in an ammoniacal solution, or one as neutral as possible, it is often necessary to remove the heavy metallic oxides or the earths present (according to Table VI.), by which means metallic acids are found, as well as phosphoric or oxalic acid combined with alkaline earths. The quality of the base often excludes the presence of one or more acids, thus rendering search for them unnecessary; generally an acid cannot be present in a neutral or acid solution which already contains the same metallic oxide that must serve as precipitant for this acid; e. g., no sulphuric acid, detected by baryta, can be present in a soluble baryta compound; no chlorine in a silver compound, soluble in acids, etc. (For exceptions in alkaline solutions, see Table XII. below.) It is evident that in any compound such acids as have been added (for solution or neutralization) need not be sought; in all compounds where the reagent can act as precipitant through its acid (or halogen) the nitrate is used; e. g., in compounds of silver, of lead, or of mercurous oxide, baric nitrate is used (instead of baric chloride). (See continulation, Table XIII.) Are Precipitated by Baric Are Precipitated by MagAre Precipitated by Acloor- Chloride Are Precipitated by Calcic Chloride: nesic Sulphate (or Baric Nitrate): (or Magnesic Chloride): From their soluble compounds, gene- om the soltion peviousy acidulated Only from neutral solution. From neutral and from acetic solution. n the presence of ammonic chloride rally showing alkaline reactions. with chlorhydric or nitric acid. The precipitate is soluble in acetic Precipitate is insoluble in acetic and free ammonia. acid. acid. Silicic Acid, gelatinous; in di- Sulphuric Acid, white, pulveru- Phosphoric Acid, white, when Oxalic Acid, white; insoluble Phosphoric Acid, white, cryslute solution only after evaporating lent; quite insoluble in water and in freshly precipitated soluble in acetic in anmmonic chloride; the precipi- talline; slowly if the solution be very the acid fluid; also precipitable by tate also forms with calcic sulphate the a cid fuid; also pnrecipitable by |acids. (In the presence of too much acid without effervescence. tatealso otms with alic sulphatdilute, soluble in all acids. and concentrated free acid baric Arsenic Acid, like phosphoric; evolves with concentrated sulphuric Arsenic Acid, like the preceding. Boracic Acid, crystalline, only chloride or baric nitrate is precipi- also easily soluble in ammonia chlo- acid CO and CO2 without blackening. The acid solution of the precipitate from concentra~ted solutions. Colors the alcohol flame green upon addi- tated; soluble in much water.) The ride. The solution in chlorhydric Racemic Acid, white, insoluble is precipitated by sulphydric acid tion of sulphuric acid. original compound gives hepar with acid is precipitable by sulphydric in atmconic chloride. Also formed by the aid of heat. Antimonic Acid, white, soluble sodic carbonate upon charcoal. acid with the aid of heat. with solution of calcic sulphate. Tartaric Acid white. Th in tartaric acid. Selenic Acid, like the preced- Fluohydric Acid, gelatinous; Tungstic Acid, white, by boil in Boracic Acid, white, easily so- the precipitat e evolves, with concen- cipitate forms slowly and only in ing, yti i wh ith z b l.ing. The precipitate, when boiled luble in amimonia chloride; not pre- trated sulphuric acid, fluohydric concentrated solution; it blackens hydric acid, blue. wit concentrated chlorhydric a cipitated from dilute solution. Tur- acid, which etches glass. on ignition. Molybdic Acid, white, soluble evolves chlorine, and sulphurous meric paper (lipped in a solution in Sulphuric Acid, white; not in excebs, with zlc aind chlorhydric acid, then precipitates out of the chlorhydric acid becomes brown on from dilute solutions; completely acid blue, finally -rown. solutionred selenium. The original drying. upon atddition of alcohol. Sulphur, yellowish orwhite; with compound gives upon charcoal be- Carbonic Acid, white, soluble Separation of Oxaic, Tartaric, Citric, and Malic Acid. the evolution of SO2 from hyposul- fore the blowpipe the characteristic i acids with effervescence. phites, and H S from metallic poly-. o 6ulphides. a selenium odor. Sulphurous Acid, white, only / Calcic chloride and lime-water are added to the alkaline reaction. Iodine, out of a solution of an Silicofluohydric Acid, like the from concentrated solutions; with iodide and an iodate or nitrite. preceding, not out of very dilute so- zinc and chlorhydric acid, evolves Fluid contains as salt of lime:- Precipitate contains as salt of lime — ui Thogacpn sulphydric acid. Also several oxides and sulpides lution. The original compound gives Citric Acid. Malic Acid. Oxalic Acid. Tartaric Acid. soluble in potassa, and cyanides or upon heating silicic fluoride and a Tartaric Acid, white, soluble in chlorides soluble in potassic cyanide. metallic fluoride, with alkalies silica ammonmc chloride and caustic po-d w If the alkaline fluid be saturated with tassa; the potassa solution of the sulphydric acid, all the acids lof te and a fluoride. precipitate becomes turbid by boil- Precipitate: Filtrate: Residue. Filtrate. metals which form sulphides insoluble ing. ] _ _ _ in acids, are precipitated, after Citric Acid, white, but only by Calcic Citrate. Calcic Malate. Calcic xalte. Calcic artte. acidulation, as sulphides. boiling tile fluid supersaturated with Of the organic acids, henzoic, uric, lime-water orammonia. and tartaric acid (the latter as acid Perrocyanhydric Acid, forms chloride, after evaporation, tic acid andcindpotassatsolution and tartaric acid (the latter as acid erroyanhydri Acid, forms by alcohol (and cupric chloride; is precipitated potassa salt) may be precipitated by slowly, soluble with difficulty in then to be further soluble in chlor- gelatinous. acids from alkaline solution. acetic acid. tested). hydric acid. S-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ TABLE XIII. DETECTION OF ACIDS. X1II. Behavior of the more important Acids towards Reagents and Indigo Solution. B. Detection of acids in compounds which ore insoluble in mates and in acids.-From the preliminary examination, the nature of the compound and the acids possibly present, must have been ascertained -Inorganic compounds (which, ignited alone, afford no carbon) are finely pulverized, and fused with fourfold weight of pure sodic-potassic carbonate, and the aqueous extract (neutralized by chiorhydric, nitric, or acetic acid), is examined according to Tables XII. and XIII. Insoluble compounds of the heavy metallic oxides may also be decomposed by digestion with ammonic sulphide, the sulphates of the alkaline earths by boiling with a concentrated solution of sodic carbonate; the filtrate contains the acid. Metallic sulphides afford sulphseric acid by treatment with nitric acid, aqua regia, or chiorhydric acid and potassic chlorate. The salts of organic acids insoluble in water, are decomposed by boiling with alkaline carbonate; and the ferric salts of volatile organic acids, also by ammonia; the filtrate contains the acids combined with the alkali, and is examined according to Tables XII. and XIII. Acids recognizable by Ferric Ohlorides Acids Precipitable by Argentic Nitrate. Acids decolorizing Indigo -~~j —-~~~ —— Acis deolorizig In precipitate is formed. A color is produced.. Only from neutral solution.. Likewise from acid solution. a. In the ppresence of free chlorhydric a. In the presence of free chldehydric The precipit ate is solusble in dilute The precipitate is insolseble in dilute a. Alosse, withoust addition of an acid. acid. acid. nitric acid. nitric acid. Free Chlorine and Bromine; Ferrocyanhydric Acid, blue; Chiorhydric Acid, white, soPerrievanhvdric Acid, brown-'Phosphoric Acid, (tribasic) lu i tlarl II n isdi yp-Hpochloric, Chlorous. In the precipita~te is decomposed by ish. Ferrous salts produce a blue yellow; also precipitable by am- lsulphite. ypochlorous Acid, as, an the precipitate is decomposed by ish. ble ~sipht. Hypociiorods Aciddas well as potassa into ferric oxide and potassic ferrocyanide. precipitate. monic chloride, ammonia, and mag- Bromhydric Acid, like the Hypochlorites; aid free Nitric Sulphoyanhydric Acid, in- nesic sulphate. preceding. The original compound Acid not too dilute b. In neutral solstions, or those con- tense blood-red, not removed by Arsenic Acid, brownish-red colors carbonic bisulphide reddish- Also alkaline Metallic Suiphtaissing only free acetic acid. yellow after the addition of some much chlorhydric acid, but is by the original compound is precipitable chlorine water. ides and Caustic Alkalies. (If free ctlorhydric acid be present, add sodic acetate.) mercuric chloride, by H2S lodohydric Acid, yellowish, Phosphoric Acid,/ yellowish- ~nl so Ar~senious; Acid, egg-yellow insoluble, in ammonia (with removal b. On the addition of an acid (chlor whote; insolule in acetic acid, syli- b. Only in seetral solutios. of colors). The original conipound hydric 6r sulphseric) asd heating. ble in cholrhydric acid arid in ferric (The color vanishes on addition of chlor- otherwise like the preceding. renders starch blue, with iitrous acet:ate and in ferric chloride. hydric acid). Chromic Acid, red; the origi- acid. Arsenic Acid, like the preced,- Acetic Acid, reddish-brown; the nal yellow or red compound becomes Iodic Acid, white, soluble in lion netallic chlorides. ing; thle origiiial compound gives original salt warmed with alcohol green by 0 1ammonia, prcipitable therefrom by Nitrates; dark color with fer-.n 2 802as opun iesoiilu ntwtrldwihacoo;ee y8), ORAgt. The original compoundrosuphtanSlhri with sodic carbonate an alliaceous and sulphuric acid has the odor of Oxalic Acid, white, insoluble in Sgives (if. metallic iori ide be pre- c odor. -~~~~~~~~~~~~~~~~~~~~~~ies(famtllcidd epr-ru upate and sulphuric acid odor, acetic ether, acetic acid.'lbs lime Salt is like- sent), with acetic acid and starch the nitrates of theheavy metals and Tannic Acid, dark blue. The blue iodide of starch. earths when heated alone, t origginal compound is precipitated by Formic Acid, like the preced- wise insoluble in acetic acid. Cyanhydric Acid, white, so- the alkalies and alkaline earths when 1 ora'cic Acid, white, soluble in luble in amnlonia and in sodic hypo- heated with dry cupric sulphate targentic or mercuric oxide with acetic acid; green alcohol flame after sulplilte. The original fluid gives, evolution of carbonic acid. the addition of sulphuric acid.. with a mixture of lerrous and ferric give red fumes. Boracic Acid, yellowish. Tur- salts, potassa, and chlorhydric acid, lodates; the dry compound gives meric piper dipped in the chlor- Sulphurous Acid, like the pre- Sulphurous Acid, white, black- 1Prussian blue. hydri - acid solution becomes, after cediig; on boiling, the color van- weniig on boiling. Ferrocyanhydric Acid, white, with sulphuric acid and ferrous suldrying, brown, ard then upon mioist- ishes without precipitation. The insoluble in anniiionia.'The original phate violet vapor of iodine. eiiing with a drop of potassa solu- compound, upon the addi- Hyposulphurous Acid, white, compound gives immediately with Bromates; give with sulphuric tion black, darkens rapidly.; -soluble ii excess ferric salts, Prussian blue. tion of chlorhydric acid, has the of the hyposulphite. Ferricyanhydric Acid, red- acid brown vapor of bromine. Benzoic Acid, light brown. The odor of sulphie. errurahus c Aidire. 01origInal clicentmated solntion is pre- odor of suliurous acid. dish-brown. Ferrous salts give a a. By hailing or warming with concipitiated crystalline by chlorhydric Meconic Acid, blood-red, un- dark blue precipitate. y ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~centrated chlorhydr~ic acid eov acid, changeable by anric chloride. * All these piecipitates are ntluble in Sulphcyanhydric Acid, white; Succinic Acid, like the pre-,. ammonia. The salts of pyrophospI/horic difficultly soluble in annin1Oiiia; the (bleaching) chlorise cediing. The concentrated solution Gallic Acid, black. The origi- and metaphosphmoric acid piecipitate ar- oriinal solution becotnses with feiric All the preceding compounds, further:of the anmmonia selt (obtained by nal solution is not precipitated by gentic nitrate wiits; the tatter give, after chloride, blood-red. Chronates and Vanadates, digestion of the ferric salt with am- gehatine. the addition of acetic acid, a precipttate Suiphydric Acid, black, in Seleniates, tiliiab) is precipitated by baric dhuo- with albumen. In concentrated solution soluble, in amItnmonla; plumbic and ride in the presence of alcohol and acetates are also prscipiiated by argentic cupric salts also give black precipi-free anioiiia. nitrate. tates. Alkaline sulphides give, with Superoxides, and the Acids sodic nitroprusside, a purple color, of Manganese. TABLE. XZIV. [SECOND METHOD.] DETECTION OF METALLIC OXIDES. For the treatment of the Filtrate from the H2S precipitate of Table VI. instead of the method of that Table. (c. F. H.) The substances precipitated, according to Table VI. by ammonic sulphide and ammonia, in presence of ammonic chloride, and which are subsequently separated into two groups, in examination according to Table VIII., may be as readily and completely separated into two groups in the precipitation of the H2S fltrate, by employing ammonia and ammonic sulphide, in presence of ammonic chloride, successively, instead of together, as follows: Boil the filtrate from H2S precipitate, until all the H2S is expelled, then add a few drops of nitric acid, and boil for an instant (to convert ferrous into ferric salts), and add Ammonic Chloride and Ammonic Hydrate (ammonia). lTo the filtrate add Precipitate may contain ccammonic sulphide and warm until'the, supernatant liquid'is clear, (if of a dark brown color the presence of nickel is indicated.) Ferric, chromic, uranic oxides; alumina, glucina; baric, strontic, calcic phosphates and /' oxalates; magnesic phosphate; aluminic, chromic, iron, and manganous phosphate; (man Precipitate, Filtrate. ganous oxide, traces; calcic fluoride; borates of alkaline earths, in part;) [cerous, lan- Cobaltous sulphide, l Manganous sulphide, flesh-colored. Treat as directed for thanic, didymic oxide; yttria, thoria, zirconia, titanic acid.]It Nickelous sulphide, black Zincic sulphide, white. filtrate from ammonic Digest with concentrated solution of ammonic carbonate, Treat with cold, dilute, chlorhydric acid:- sulphide precipitate in ________'__ ____________ __ _________ Table VI., by precipiSolution, contains Dissolve the Residue, Boil the solution (Mn, Zn) Residue (Ni, Co). tating Ba, Sr, Ca by eUranic oxide,~ 1 in (boiling) chlorhydric acid, and boil until all CO2 has been expelled, to expel H2S, and add NaHO to excess: — Wash, dissolve in aqua ammonic carbonate, | [Cerous oxide,] | | and add when cold Na~HO (or'IKilO). i regia, evaporate al-land examining the fil[Lanthanic oxide,] jJ with KCy, and add, the alkalies. [Didymic oxide,] Boil the filtrate for some time. Precipitate, may Precipitate, Filtrate, with Cy, and addthe alkalies. when cold, slight ex[Yttria,] | contain ferric oide, Manganese (traces of Zinc. Add H2S; cess of sulphuric acid. [Thoria,] Precipitate, Filtrate, ferric phosphate; ba- Ni and Co). Test with white precipitate. Non-crystalline preci[Zirconia,] Chromic oxide Acidulate with HCI, ric, strontic, calcic, blowpipe, and as di- Test with the blowpitate. [Glucina,] j [Glucina]. and add ammonic car- magnesic phosphate, rected in Table VIII. pipe. Chromic phosphate. etc. Nickel. Te st with blowpiphe. honate Dissolve in a little Test with the blow* See remarks, Table Test with blowpipe. Precip e, HC1, and test in sepa- pipe, or potassic niVIII., on these substances. |A i hlumina, aluminic t rate portions as direct- trite, etc. See Table phosphate. ed in Table VIII. VIII. Filtrate, [Glucina] only if not previously digested with ammonic carbonate. Test with blowpipe. t Whilst chromic oxide and phosphate, in a pure state, precipitated in the cold by alkalies redissolve easily and completely, and reprecipitate on boiling, not a trace of Cr2,,, unless present in very great excess, will pass into solution, if ferric oxide be present, and its separation from Fe2Os in this way is impossible. Whether glucina in solution in KHO will precipitate on boiling, or remain in solution with A1203, depends on the concentration of the liquid as well as a moderate alkalinity. (If the precipitate has been treated long enough with ammonic carbonate, the glucina will be found in the solution, and not in the precipitate of the sesquioxides.) The following treatment of the ammonia precipitate includes also the detection of titanic acid, a matter of importance in many cases. Dissolve the ammonia precipitate in as little sulphuric acid as possible (or fuse the original finely pulverized substance with KHSO,. and extract the mass with cold water), dilute largely with water (about 1000 c. c. for 0.2 gramme TiO2 in nearly neutral solution), saturate the liquid with H2S gas, and boil thoroughly for about an hour. Precipitate, Titanic acid; filtrate FeO, Cr20O, H3PO4, and small quattities of alkaline earths, phosphates, etc. (If alkaline earths were originally present the H3PO4 will remain completely with the sesquioxides if they are present in sufficient quantity, and the earths will be found in the ammonia filtrate.) Oxidize the filtrate from TiO2 with HNO3; precipitate it by ammonia, and after drying the precipitate, fuse it with NaC(Os and NaNO3, and treat with water. The residue will contain Fe2O,; the solution alumina, chromic and phosphoric acids, combined with alkalies. Add NH4Cl: Precipitate A1203;' and part or all of the H3PO4 (to be detected by ammonic molybdate). Acidulate the filtrate with dilute acetic acid, and add BaCl: Precipitate BaCrO4; filtrate BaHPO4 (if phosphates were present) precipitable by ammonia. Absence of TiO2 would simplify the process. If A1203 is present, it will all be found in the solution of the fused mass, provided the fusion has been prolonged enough.