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New Method for the Detection of Copper, &c.

FILTRATE.

Contains Cu and Cd; divide into equal parts.

Solution A.

Add a few drops of (NH4) HO, then (NH4)2S and gent"Bismuth ly warm; a yellow ppt. = CdS. Cd.

Flux" (KI+S).

Bi.

Solution B.

Add HCl(dil) to
strong acid reac-
tion; a reddish
ppt. = Cu2FeCy6.

Cu.

The basis of the above scheme may be stated as follows:

1. The complete precipitation of copper, cadmium, and bismuth by potassium ferricyanide.

2. The solubility of copper and cadmium ferricyanides in potassium cyanide.

3. The decomposition of bismuth ferricyanide into bismuthic hydroxide by the action of potassium cyanide. 4. The insolubility of cadmium sulphide and the solubility of cupric sulphide in potassium cyanide.

5. The insolubility of copper ferrocyanide and the solubility of cadmium ferrocyanide in hydrochloric acid.

The Chemical Reactions.

White.

(a). 6KCy.Fe2Cу6+Bi2(NO3)6= Bi2Fe2Cу12+6KNO3. Yellowish white.

(b). 6KCy.Fe2Cу6+3Cu(NO3)2= Cu3Fe2Cy12+6KNO3.

White.

(c). 6KCy.Fe2Cу6+3Cd(NO3)2 = Cd3Fe2Cy12+6KNO3. (d). BizFe2Cy12+8KCy+6H2O=2Bi(HO)3+

2(4KCy.FeCy2)+6HCy+Cy2.

(e). CuzFe2Cy12+14KCy=3[(KCy)2.CuCy2]+

2(4KCy.FeCy2)+Cy2. (f). Cd3Fe2Cy12+14KCy=3[(KCy)2.CdCy2] +

2(4KCy.FeCy2)+Cy2.

(g). (KCy2.CuCy2+4HCl=CuCl2+2KCl+4HCy. (h). 2CuCl2+4KCy.FeCy2=Cu2FeCy6+4KCl. (i). CuS+4KCy=(KCy)2.CuCy2+K2S. (j). (KCy)2.CdCy2+ (NH4)2S = CdS+

(KCy)2(NH4)2Cy2

(k). (KCy)2(NH4)2Cy2 = 2K(NH)Cy2 or 2KCy-3(NH4)Cy2

I proved by experiment that when copper, cadmium, and bismuth ferricyanides are treated with an excess of KCy, potassium ferrocyanide is formed (see Equations d, e, and f).

It is difficult to say whether Equations g and h represent the exact chemical change that takes place, since there is a discussion in regard to the compound called "Hatchett's Brown" or copper ferrocyanide. Reindel gives its composition as Cu3K2FeCy12 (see J. Pr. Chem., ciii., 166), while this formula is called in question by Wyrouboff, who gives the formula Cu2FeCy6, probably with 6 mol. H2O (see Bull. Soc. Chim. [2], xii., 98; xiv., 145).

The qualitative reactions for cadmium and bismuth have always been a source of annoyance, and the valuable aid of the blowpipe has almost invariably been used by the chemist to decide the presence of these elements. While recognising the delicacy of the blowpipe methods for the detection of copper, cadmium, and bismuth, and the blowpipe as a most useful auxiliary in qualitative

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17

work, I think the chemists will bear me out in the statement that the test-tube, and not charcoal, is the proper place for the detection of substances in a qualitative laboratory, and that the blowpipe methods should only be used as a confirmatory test. In order to illustrate this point I will state that, were entire reliance placed in the bismuth flux" for the detection of bismuth, errors might arise; for example, mercury and antimony-both members of the H2S group-give, under certain conditions, a red coat with the "bismuth flux" (4 parts S +1 part KI).

By taking powdered stibnite (Sb2S3) and mixing it with 50 to 60 per cent sulphur, I succeeded several times in obtaining a very fine red coat, closely resembling the bismuth coat.

The objections to my scheme, so far as I have been able to find out, are, that students do not seem to think there is much difference between "gently warm," as I term it in the scheme, and to boil hard for about half-anhour, thus causing a decomposition of the cyanogen compound and a deep blue colour. The second objection is the evolution of cyanogen and hydrocyanic acid.

Although I have not applied this method in quantitative separations of copper, cadmium, and bismuth, yet I see no reason why it should not be a good one, especially for cadmium and bismuth.

The excellent method of precipitation of copper by use of the battery seems to leave nothing to be desired in this direction.

Fresenius gives four methods in which bismuth may be weighed, placing the teroxide first on the list. He says the method gives accurate results, though generally a trifle too low, owing to the circumstance that bismuth carbonate is not absolutely insoluble in ammonium carbonate.

He also adds, "Were you to attempt to precipitate bismuth by means of ammonium carbonate from solutions containing sulphuric acid or hydrochloric acid, you would obtain incorrect results." Every author I have consulted says Bi2(HO)6 is insoluble in KCy: it seems, therefore, highly probable that the decomposition of bismuth ferricyanide by KCy into Bi2(HO)6 may be used as a quantitative method for the estimation of this metal. Furthermore, the presence of both hydrochloric acid and sulphuric acid does not seem to interfere with the complete separation of the hydroxide.

I have quite recently noticed that if an excess of potassium cyanide is not added, a ferrocyanide of copper separates on standing some time: whether this is a proto or diferrocyanide I am unable to say. I have also noticed that occasionally a few particles of a dark-looking compound separate, when solid potassium cyanide is used to dissolve the ferricyanides of copper and cadmium. The formation of this compound occurs immediately around the solid potassium cyanide, but seems to disappear by shaking or gently warming.

In regard to cadmium, Fresenius says it is weighed either as an oxide or a sulphide, giving the preference to the oxide. Yet he states that all compounds of cadmium, without exception, may be weighed as a sulphide, and the results are accurate.

The method of precipitation by hydrosulphuric acid has several objections; for example, you must not have a strong acid solution, much HCl and HNO3 interfering with the complete precipitation.

The cadmium sulphide is almost invariably contaminated with sulphur, which must be dissolved out with carbon disulphide, which the chemists will, I think, generally agree with me is more or less a troublesome and disagreeable operation; or the sulphide may be boiled with sodium sulphite.

Sulphur does not separate in a solution containing potassium cyanide, when a metal is precipitated by hydrosulphuric acid, or ammonium sulphide; therefore my mode of procedure would not have the objection stated above.

18

British Pharmaceutical Conference.

PROCEEDINGS OF SOCIETIES.

BRITISH PHARMACEUTICAL CONFERENCE.
MEETING OF EXECUTIVE COMMITTEE.
July 5th, 1876.

PRESENT-Professor Redwood, President ; Messrs. Frazer, Williams, Carteighe, and Schacht, Treasurer; Professor Attfield, Honorary Secretary; and Mr. Davies, Assistant-Secretary.

Thirteen candidates were elected to membership. The names of several members, whose subscriptions were more than two years in arrear, and to whom repeated written applications had been made by the secretaries, were removed from the lists.

Twenty-six subjects proposed for research were received and considered.

Professor ATTFIELD suggested that some competent member should be employed to revise and somewhat elaborate the "subjects for papers" named in the current list issued by the Conference. In the course of thirteen years the Conference had proposed some two hundred subjects for research, of which nearly one hundred had since been investigated, resulting papers forming about one-third of the three hundred papers which had been read at the twelve annual meetings of the Conference. The one hundred or so of subjects now on the list, especially the fifty or sixty which had been down for several years, required careful revision, information concerning any work already accomplished being added to each subject, and some hints given as to the direction which further investigation should take. Probably a few of the subjects might now be excluded from the list altogether. The secretaries were ordered to give effect to the suggestion.

The EDITOR reported good progress in the preparation of the MS. of the "Year Book of Pharmacy" for 1876. Professor ATTFIELD reported that since the previous meeting of the committee he had issued about 2500 copies of the current Year-Book.

NOTICES OF BOOKS.

Legal Chemistry: a Guide to the Detection of Poisons Examination of Stains, &c., as applied to Chemical Jurisprudence. By A. NAQUET. Translated, with additions, by J. P. BATTERSHALL, Nat. Sc.D., with a Preface by C. F. CHANDLER, Ph.D. M.D., &c. New York: Van Nostrand.

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THE title-page of this book shows a step in the right direction. We are glad to see such misleading and illogical terms as legal medicine," "forensic medicine," and "medical jurisprudence replaced by the more accurate expressions used by our authors. The plan of the work before us is extensive, almost too much so for its compass of 178 pp. In addition to toxicology we find instructions for the detection of adulterations in articles of food and medicine, for the examination of blood-stains, &c., on weapons, clothing, &c., the determination of the nature of hair, and of its original colour, the examination of writings, of sympathetic inks, of suspected coins and alloys, and of human remains in the ashes of a fire-place. The section on alimentary and pharmaceutical substances may be pronounced thoroughly unsatisfactory. It embraces merely flour and bread, olive, colza, hemp-seed, and linseed oils, milk, wine, vinegar, and sulphate of quinine. The remarks on milk are evidently based upon old and erroneous analyses, since M. Naquet states that "good milk leaves upon evaporation 7'5 to 9.5 per cent of solid matters." We have heard a complaint that even the

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standard of the Society of Public Analysts (11.5 per cent) has proved an encouragement to fraud, since milks are now carefully let down to this point. The lactometer, the lactoscope, and Marchand's instrument have now merely a historical interest, and it is surprising that they should be noticed in a practical manual. The directions for the examination of bread are little better. An analyst who should undertake the detection of alum by the method indicated in the text would be equally successful in its presence or in its absence. The reader is not even and silica in his caustic alkali. cautioned against the very possible presence of alumina The translator, to do him justice, adds a foot note, in which some of the shortcomings of the author are supplemented. Under wine, we are told that the "most common adulteration is the addition of water!" With us, at least, the most common adulteration is the addition of extraneous alcohol, generally rich in amylic compounds. On the detection of this fraud and on "plastering" nothing is said. should be left out of sight does not appear. Why coffee, chocolate, tea, sweetmeats, &c.,

The section on the recognition and discrimination of blood-stains is more in harmony with modern requirements. The author, however, observes:-"In the present state of science it is impossible to discriminate chemically between human and animal blood. M. Barruel, it is true, is able not only to accomplish this, but also to distinguish the blood of the various species of animals by its odour. But this test has a somewhat hypothetical value for scientific purposes."

We have all due respect for the nose as a preliminary instrument of qualitative research. Nor do we question that the flesh and the blood of different species, or at least groups of animals, may have a distinct specific odour. But remembering that the sense of smell varies exceedingly in delicacy, and that the whole amount of blood involved in such investigations is often very small, we think this test utterly inadmissible.

Nor cah we speak with any favour of the instructions for the detection of human remains in the ashes of a fire-place. The author, indeed, practically admits their worthlessness when he says-"These indications, however, are reliable only when the certainty exists that the bones of animals have not been consumed in the same fire-place." How often is this certainty so absolute that a judicious chemist could presume to infer the presence of human remains from the occurrence of nitrogenous matter and phosphate of lime? The author justly points out the fallacious character of another supposed indication:-" It has been stated that the disengagement of sulphuretted hydrogen upon treating the ashes with sulphuric acid is an indication that the combustion of a human body has occurred (!) This reaction is, however, valueless, inasmuch as coal and certain vege table ashes likewise evolve the same gas when subjected to the same treatment." We cannot help wishing to know what chemist can first have made so absurd a suggestion.

The section on the chemical examination of written documents supposed to have been tampered with is very interesting. The following passage exposes an ingenious fraud, against which the public should be put on their guard "The expert may possibly be called upon to give evidence as to the existence of a trompe l'œil, as was the case in the trial of M. de Preigne, which took place at Montpellier in 1852. A trompe l'œil' consists of two sheets of paper glued together at the edges, but having the upper sheet shorter than the other, which, therefore, extends below it. This species of fraud is executed by writing unimportant matter on the upper sheet and then obtaining the desired signature, care being taken that it is written on the portion of the paper projecting below. The signature having been procured it is only necessary to detach the two sheets in order to have a blank paper containing the signature, over which whatever is desired can be inserted. The expert upon placing

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CHEMICAL NEWS,

July 14, 1876.

Determination of Manganic Oxide.

pieces of moistened paper upon the suspected document noticed that they adhered to certain points, and that these formed a border around the paper, but passing above the signature."

We think that without great nicety of manipulation on the part of those carrying out this fraud the signator might easily notice the greater thickness of the body of the document as compared with the part where he is requested to sign.

One of the most valuable features of the work is an appendix, added by the translator, containing the bibliography of toxicology and its kindred branches of analytical chemistry. Not only independent works are here given, but all memoirs and papers in the leading scientific journals and in the transactions of learned societies, the whole forming a most useful index.

The Retrospect of Medicine. Edited by W. BRAITHWAITE, M.D., and JAS. BRAITHWAITE, M.D. Vol. lxxiii. January to June, 1876. London: Simpkin and Marshal. THIS half-yearly issue, though replete with matter interesting to the medical practitioner, contains nothing of importance to the chemist. We find chloride of lead recommended as a deodoriser and disinfectant, and pronounced "the most powerful and economical agent for eliminating sulphide of hydrogen from the atmosphere, as well as from all organic matter in a state of decomposition or putridity."

Remarks on the Purification of Water and other Things. By LEWIS THOMPSON, M.R.C.S. Newcastle-uponTyne: Daily Journal Office.

FOR the purification of water the author recommends aluminite, the tribasic sulphate of alumina, or the same compound artificially prepared. He is, however, no believer in the "disease producing matters in water," and considers that the "proofs and evidences have wholly failed to establish any connection between the water and any disease whatever." There is no outcry made about purifying the air, because there is nothing to be got out of it. It won't pay, and consequently it cannot be 'sanitarised.'"

66

We commend the following passage to the attention of all who pay, or are intending to pay, millions for having their sewage carried out to sea, and poured, as they fondly think, into deep water:-" There is a very interesting and even amusing circumstance connected with the waste of fertilising matters by the barbarous system called sewerage, and this circumstance admits of a happy illus. tration in the case of the existing metropolitan waste. We will now examine what must of necessity happen when the London sewage is sent from the mouth of the Thames. That sewage is lighter than sea-water, and consequently floats upon and does not mix with it, a fact very well known to the captains of our ships, who, though perhaps prevented by fogs from seeing the land, know well when they are approaching the mouth of a river by the change in the colour of the water. The sewage, therefore, floats on the surface of the sea, and the most valuable portions of the sewage, which are also the most offensive, are not destroyed or got rid of in the way expected by the sewage scheme projectors, but find their way to the nearest shore, where they serve as food for animals. And what are the names of those animals? The two most numerous are the mussel and the oyster; the very animals which are collected by man and sent up to London as food for the inhabitants, thus showing that an

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CORRESPONDENCE.

REACTION OF CHROMIC ACID WITH HYDRIC PEROXIDE.

19

To the Editor of the Chemical News. SIR, I think that the result of a few observations on the action of hydric peroxide upon chromic acid may not prove uninteresting, and may possibly be useful in the course of a qualitative analysis. It has been before observed that hydric peroxide, when poured into a solu tion of chromic acid, produces a considerable change in the liquid. If, however, the liquid be first treated with a small quantity of ether, and after the addition of the hydric peroxide it be well agitated, a blue colour will be apparent in the etherial portion of the solution. This reaction I have been led to use as a test thus. To the solution in a small test-tube I add, first, a quantity of ether sufficient to form a layer of from 3 to 4 millimetres in thickness. I then add a few drops of a solution of hydric peroxide, and agitate the whole together by inversion. If no blue colour is then apparent in the etherial solution I add a few drops of strong hydric nitrate and a few more drops of hydric peroxide, and re-agitate the whole, when, if a chromate be present, a blue colour will develop itself in the etherial layer. I have thus been enabled to detect the presence of chromic acid in a solution containing only set of its weight of potassic anhydro-chromate, corresponding to about of chromic acid. As far as I have seen, this test is unaffected by the presence of nickel, cobalt, iron, manganese, aluminium, and other metals likely to occur in connection with chromium. It is, however, affected by the presence of hydric acetate, which causes the ether to dissolve in the aqueous solution, thereby rendering the blue colour very much less distinct. It is also necessary for the success of the test that there should be no free alkalies present, as they completely discharge the blue colour from the etherial solution.—I am, &c., R. H. C. NEVILE.

Chemical Laboratory,
Catholic University College, Wright's Lane,
Kensington.

DETERMINATION OF MANGANIC OXIDE.

To the Editor of the Chemical News. SIR,-In reply to Mr. Allen's query in the CHEMICAL NEWS (vol. xxxiv., p. 8), that gentleman will find the information he requires in any standard work on analytical chemistry-for instance, in H. Rose, vol. ii., p. 110 (French edition). But to save him the trouble of referring to any work, I may state that I discovered the manganic oxide in a very simple manner; namely, by determining in the first place the total quantity of oxygen, and in the next the total quantity of manganese. These two data are quite sufficient for the purpose. I think Mr. Allen might hesitate before he accuses chemists of counting oxygen twice over, especially when demanding advice upon so very simple a subject.—I am, &c., T. L. PHIPSON, Ph.D. London, July 9, 1876,

INNS OF COURT PUMPS.

To the Editor of the Chemical News. SIR,-You have propable observed in the Daily News of the 27th ult., a statement by Mr. W. Foster that New River water contained, “a short time ago," o'004 gr. of ammonia per gallon, or, to express this in more con

Much of this, quaintly and humorously as it is put, is venient language, 00057 part per 100,000. I have only too true.

recently made a number of analyses of New River water

20

Chemical Notices from Foreign Sources.

through.

{CHEMICAL NEWS,

July 1876.

and found it remarkably free from ammonia, containing | out, that a stem is more active where it has been cut even less than o'001 part per 100,000. Referring also to the Registrar General's Reports of the present year, as far as I have them at the present moment before me, I find that New River water was free from ammonia in January, February, and April, containing in March only o'001 part per 100,000. As the figure stated by Mr. Foster would convey to any one at all acquainted with London water the notion of a most alarming deterioration of the New River water, you will I hope excuse my troubling you with these lines.

Mr. Foster's statement that nitrates are among the characteristic constituents of sewage is evidently a slip of the pen, the reverse being the case.-I am, &c.,

Analytical Laboratory, 4, Hart Street, Bloomsbury, London, July 8, 1876.

GUSTAV BISCHOF.

DR. J. W. HEARDER, F.C.S.

To the Editor of the Chemical News. SIR,-May I ask why Mr. R. Meldola should have selected Mr. Hearder in particular as having degraded the Chemical Society by use of the F.C.S. after his name in an advertising or trade pamphlet.

There are two trade advertisements in your impression of this week containing these initials, yet I think it would be very hard to charge Mr. J. J. Griffin (one of the advertisers) with trumpeting the F.C.S. for trade purposes; it would be useless to do so, for the high character and scientific attainments of that gentleman are too well known. Mr., or more correctly speaking, Dr. Hearder is well known in the West of England as a man of great ability, and especially is he respected and his talents recognised by the inhabitants of Plymouth, where he has laboured hard for the progress of science, and the number of his pupils that have obtained honours in chemistry and experimental physics at the public examinations will speak for itself.

Dr. Hearder has been blind for many years, and anyone who has attended his lectures, carried out, as they must have been, under great difficulties, will agree that instead of bringing discredit on the Chemical Society he has been an honour to it. I am, &c.,

F.C.S.

FORMATION OF OZONE BY THE CONTACT
OF PLANTS WITH PEROXIDE
OF HYDROGEN.

To the Editor of the Chemical News. SIR,-Under the above heading, Mr. S. Cohné, in the CHEMICAL NEWs (vol. xxxiv., p. 4) describes a few simple experiments, which, according to his interpretation, demonstrate that plants, by contact with peroxide of hydrogen, develop ozone. But the evidence he adduces is not sufficient to my mind to justify his deduction.

The results he obtained are as readily explicable on the view that the oxygen generated carries up with it a thin film or cloud of the aqueous solution containing peroxide

Animal fibrin is known to have this character in a high degree, and, indeed, it serves as one of the best tests for peroxide of hydrogen, while the latter serves a reciprocal purpose for fibrin. All facts regarding the various states of oxygen are of interest, because it is probable that oxygen may exist in several other forms to those with which we are at present acquainted.

Thus Odling has (CHEMICAL News, vol. xxvi., p. 296) suggested the existence of a variety of oxygen, "the weight of any given volume of which, like that of a given volume of phosphorus vapour, shall furnish the weight of the element contained in four such volumes of its several simplest compounds;" and of yet another variety of oxygen, "the weight of any given volume of which, like that of any given volume of mercury vapour, shall furnish but the weight of the element contained in the same volume of its several simplest compounds."

Schönbein viewed every slow oxidation as attended by the formation of ozone, and taking the use of this word to imply, not the definite body bearing that name, but a state of activity of oxygen, this appears to be true. Moreover, I have noticed that peroxides, such as those of lead and manganese, variously prepared and of accepted purity, when heated in vacuous tube, give oxygen which has the power of liberating iodine from potassic iodide. But not enough is known of these matters to admit of an acceptable interpretation.—I am, &c.,

CHARLES T. KINGZETT. Pathological Laboratory, 68, Earl's Court Road, Kensington, W.

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SOURCES.

PUBLIC ANALYST.

of hydrogen, which fatter body acts upon the potassic CHEMICAL NOTICES FROM FOREIGN iodide (which was the reagent he employed as a test) with the same result as ozone. Inasmuch, therefore, that the test Mr. S. Cohné employed is one as readily susceptible to the influence of peroxide of hydrogen as to that of ozone, it is premature to write of the formation of ozɔne in this way.

I

It is in all probability a simple decomposition of peroxide of hydrogen into water and nascent oxygen. have on several occasions conducted such experiments, and have further thought that the decomposing influence resided in the fibrin of the plant, an idea which derives some support from the fact which Mr. S. Cohné points

NOTE.-All degrees of temperature are Centigrade, unless otherwise expressed.

Comptes Rendus Hebdomadaires des Seances, de l'Acade:nie des Sciences. No. 24, June 12, 1876. Experimental Criticism on Glycemia: PhysicoChemical and Physiological Conditions to be Observed for the Detection of Sugar in the Blood.-M. C. Bernard.-Not adapted for abstraction.

CHEMICAL NEWS, July 14, 1876.

Chemical Notices from Foreign Sources.

21

Absorption of Free and Pure Nitrogen and Hydro- | brown, methyl-aniline a red-brown, and nitro-benzin a gen by Organic Matters.-M. Berthelot.-The author describes his experiments and the apparatus employed. Formation and Decomposition of Binary Compounds by the Electric Effluve.-M. Berthelot.-The action of the effluve, like that of the spark, tends to resolve compound gases into their constituents with the production of phenomena of equilibrium due to the inverse tendency to re-combination.

Electric Transmissions through the Soil.-M. Th. du Moncel.-Not capable of useful abstraction.

Certain New Experiments made with the Radiometer of Mr. Crookes.-M. A. Ledieu.-The radiometer was found to continue revolving when submitted exclusively to a pencil of luminous rays falling parallel to its axis. The author, however, does not draw the conclusion to which a superficial and systematic examination of this result might seem to lead. The experiment performed by M. Salleron at the suggestion of the author condemns decidedly the doctrine of emission as an explanation of the

movement of the radiometer.

Law of Dulong and Petit.-M. Terreil.-The product of the specific heat by the chemical equivalent is a constant, on condition that all the bodies are taken of the same gaseous volume and before all condensation. The specific heat of elementary bodies taken at the same volume in the gaseous state is inversely as their chemical equivalents. The specific heat of compound bodies, under the same condition, is inversely proportional to their chemical equivalents, and proportional to the condensation which the gaseous volumes of the simple bodies constituting them have undergone on combining. Simple or compound bodies which have lost the gaseous state have a specific heat double that which they possessed when in the state of gas.

Phenomena of Electric Oscillation.-M. L. Mouton. -Not adapted for abstraction.

On Propylenic Chlorhydrines and on the Law of Addition of Hypochlorous Acid.-M. L. Henry.-A purely hypothetical paper, in which the author combats the views of M. Markownikoff.

Elementary Analysis of Electrolytic Aniline-Black. -M. Fr. Goppelsræder. The black analysed had been obtained by passing the galvanic current through_an aqueous solution of pure hydrochlorate of aniline. The deposit formed at the positive electrode was purified by successive treatments with water, alcohol, ether, benzin, and again with alcohol. After this purification the substance was then dried at 110°, and appeared as a velvetblack powder. The mean result of 11 analyses was :

Carbon Hydrogen Nitrogen Chlorine

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71*366 5.241 15'327 8.941

brown-red. Under analogous treatment alcohol takes a violet colour, the liquid giving the following reactions:It is decolourised by hydrochloric and sulphuric acids, but the colour returns after neutralisation with ammonia. Chlorine water and sulphurous acid destroy it; a small quantity of caustic potassa turns it blue, whilst an excess of the reagent renders it a violet-red. Nitric acid gives it a brown-violet shade, and acetic acid a brown, which returns to violet on saturation with caustic potassa. In like conditions the black is also attacked by iodide of ethyl, but the changes occasioned require further examination.

On Anthraflavon and an Accessory Product of the Manufacture of Artificial Alizarin.-M. A. Rosenstiehl. The author showed in 1874 (Comptes Rendus, xxix., p. 764) that the anthraflavon of Barth and Sennhofer if melted with caustic potassa gives simultaneous rise to two colouring matters, one of which, soluble in benzin and in alum water, dyes mordanted tissues shades bordering upon those of alizarin, whilst the other, insoluble in the same liquids, approaches purpurin; the shades obtained in dyeing are, in brightness and solidity, comparable to those of madder. The former of these colours is produced in such small quantities that its examination has not been hitherto possible. The latter is more plentiful, and is an isomer of purpurin approaching the isopurpurin or anthrapurpurin Anthraflavon itself is a mixture of two of Perkin. isomers of alizarin distinguished by their behaviour with bases. The one forms a soda salt very soluble in water; it dissolves in baryta water, which it colours a deep orange yellow, combines with gelatinous alumina to form an orange lake, and if melted with caustic potash between 135° and 150° it forms the isomer of purpurin just mentioned. The other yields a soda salt sparingly soluble, and readily crystallisable; it is insoluble in cold baryta water, does not combine with gelatinous alumina, and if melted with potassa at the same temperature it does not give rise to a colouring matter; a little only is formed at a higher temperature, with the destruction of a large proportion of the substance. This second body can be obtained in the form of fine silky needles, which in bulk present the yellow colour of chromate of lead, and recalls the aspect of chrysophenic acid. This body is identical with an accessory product of the manufacture of artificial alizarin from the works of Przibram and Co., of Praz.

Bulletin de la Société d'Encouragement pour l'Industrie Nationale, No. 30, June, 1876.

Deposits of Fossil Phosphate of Lime in the Departments of Ardennes and La Meuse.-An account of the phosphatic strata, and of the mining operations carried on. The phosphoric acid in the nodules varies from 16.3 to 31 per cent, the oxide of iron ranging from 4:30 to 15.65 per cent. The amount of alumina present is not specially determined but included under the somewhat vague heading "sand and clay."

Reimann's Farber Zeitung, No. 22, 1876.

100.875 This composition leads to the formula C24H21N4Cl. If boiled with a dilute solution of caustic potassa this substance loses all its chlorine and is changed into a black body of a crystalline appearance with a metallic reflection. The velvet-black powder is the mono-hydrochlorate of a base tetramine, C24H20N4, which forms mono-acid salts very readily. The black obtained by the electrolysis of hydrochlorate of aniline has the formula C24H20N4+ HCl, and that from the sulphate must therefore be, 2(C24H20N4+H2SO4). If the electrolytic black is heated vapours of aniline are given off and a violet If aniline-black is treated in colouring matter sublimes. sealed tubes at not less than 190° (up to 150° there is no action) with aniline, methyl-diphenylamin, pseudo-toluydin, methyl-aniline, and nitro-benzin; these substances attack the black and become coloured, aniline taking the violet, methyl-diphenylamin a brown, pseudo-toluydin a violet-with 60 parts of water.

J. Wagner proposes to protect alizarin steam reds from the injurious action of the steel "doctors" by adding 20 grms. sulphocyanide of potassium to each litre of colour. Sulphocyanide of ammonia is not effective.

No. 23, 1876.

Häitra is the name of a vegetable substance recently introduced into commerce for thickening colours and To prepare it for use, it is giving body to textile wares. first washed, and then boiled at 130° in a closed vessel

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