270

Dissociation Spectra of Melted Salts.

Platinum.

CHEMICAL NEWS,
Dec. 2, 1898.

LABORATORY NOTES.

By WM. FRENCH, M.A., F.I.C.

Equivalents of Metals.

IN comparing the equivalents of some metals with that of
oxygen (by conversion to oxide) for class work, I have
adopted the following method, which I find is easily per-
formed and possesses none of the difficulties of loss by
"spurting," &c., with the advantage that, as a rule, the
whole class can obtain fairly concordant results.
About I grm. of metal (copper, tin, &c.) is placed in a

hard glass test-tube (6"x") which is loosely closed with
The plug

KзFe(CN)6, no result with acid or alkaline solutions, even on boiling. K4Fe(CN6), with 1 per cent solution gives heavy crysis carefully removed, sufficient nitric acid is added to disrecently ignited asbestos fibre, and weighed. talline precipitate, forming a dark green liquid on boiling solve the metal, and the plug replaced. The tube is now turned black by NH,HO. A few drops of the reagent placed on a sand-bath, sloping at about an angle of 30°, added to a 0'2 per cent solution and boiled produces very and heated to remove excess of acid. When dry, the tube dark green solution, appearing almost black. On boiling with excess of reagent a light green precipitate results, is strongly heated over a naked flame, taking care to heat the whole of the tube in turn. which NH HO turns olive-green, then yellow, and as Cool, re-weigh, and calmore K4Fe(CN)6 is added forms a yellow solution. The culate in the usual way. A glass-wool plug will also do. green precipitate is soluble in HCl, forming a very strong ten results the number 31'91 was obtained for the equiva Working with a class of twelve students, as a mean of indigo-blue liquid: by this means less than 1 in 5000 lent of copper, the whole of them being very near to that may be detected. The other tests are good for 1 in 1000. These reactions have been found of some use in qualitative but not quite so near to the number obtained by a more number. For tin the results have been equally concordant,

work.

Mercury.

Mercuric Salts.-K3Fe(CN)6 gives no result in cold solutions, but on boiling a dark green solution is formed, which on dilution and addition of NH4HO throws down dirty yellow precipitate.

accurate method.

Possibly this method is in use, but it certainly is not common, and I would recommend those who have not

tried it as a class experiment to do so in preference to the
usual crucible or inverted funnel method so generally
figuring in the text-books.
Bury Grammar School.

K4Fe(CN)6, a white precipitate, soluble in excess; on adding more reagent it becomes a pale yellow, and on heating turns to a brilliant green, which NH,HO changes to a flesh-colour. These tests hold good for solutions of O'25 per cent strength. None of them are so delicate and On the dissOCIATION SPECTRA OF Melted useful as KI.

Mercurous Salts.-K3Fe(CN)6, light brown precipitate; turned green by boiling, and on adding NH,HO yellow. K4Fe(CN)6, white precipitate; changing to grey on boiling, and black by NH,HO. These reactions are distinct with 0.25 per cent solutions.

Lead.

K3Fe(CN)6, no precipitate; on adding NH HO yields dirty yellow precipitate, which on boiling becomes pale yellow.

K4Fe(CN)6, white precipitate; not changed by boiling or NH4HO, insoluble in acetic acid. Both reliable for o`2 per cent solutions of lead acetate.

Zinc.

K4Fe(CN)6, white precipitate; insoluble in HCl, or NHẠC, or NH HỌ.

K3Fe(CN)6, yellow "ochre" precipitate; soluble in NH HO, also in hot HCl. This is a must useful and satisfactory reagent for zinc, as the usual reagents, NH HO, (NH4)2S, NaHO, Na2CO3, and KCN, all yield white precipitate, and hence Al, which gives no precipitate with K3Fe(CN)6 or K4Fe(CN)6, is much easier distinguished from Zn by this means.

The Examination of Blood Stains. We are requested to state that at the meeting of the Society of Public Analysts to be held on Wednesday Evening next, December 7th, an illustrated lecture will be delivered by Mr. A. H. Allen, F.I.C., of Sheffield, on "The Use of the MicroSpectroscope, and the Methods of Detecting Blood in Chemical-Legal Investigations." Any persons who may be interested in the subject are invited by the Council to attend. Intending visitors who will not be introduced by members of the Society are requested to apply for tickets to Mr. E. J. Bevan, Hon. Secretary, 4, New Court, Lincoln's Inn, London, W.C.

SALTS.

METALLOIDS: CARBON.

By A. DE GRAMONT.

As with the metalloids already described, it is difficult to obtain the carbon lines in melted salts. But if the melted carbonated salt is taken out of the flame, the carbon lines appear, as do also the air lines, and their brightness appears to increase with the length of the spark-that is to say, with the increase of the difference of potential. Being desirous, however, of keeping the spark on the melted salt very short, so as to do away with-or diminish -the air spectrum, I intercalated in the secondary circuit of the coil an exciter with an adjustable attachment, to enable me to establish a sufficient difference of potential in the discharge from the condenser (which was formed of a variable number of Leyden jars).

By keeping the melted salt in a pasty state of fusion, a little above the flame, we can see the appearance of the spectrum of the carbon lines in a very distinct manner. I have compared it with that of free carbon, either in Siberian graphite and in retort carbon; this latter, however, even after treatment with acids, continued to give numerous other lines, due to impurities (Ca, Ba, Fe, &c.).

The Siberian graphite from the Alibert mines, on the contrary, gave only the carbon spectrum, the spectrum of the lines and bands of Swan mixed together, as well in perfectly dry air and carbonic acid as in pure hydrogen. But I have never found a trace of the Swan bands in the melted salts, where the carbon lines only were associated with those of the metal. It appeared to me important to make observations of a band spectrum, associated with a line spectrum, under electrical conditions, where, up to the present, spectra of dissociation only remained.

Below are given the carbon lines I obtained with the carbonates, placed in accord with the observations of previous experimenters with free carbon (see Table). So as to be quite certain as to the origin of the lines,

evident that, since we can reciprocally substitute a hexatomic alcohol for a triatomic alcohol without interfering with the estimation as far as the calculations go, we estimate in this case, not the associated acid body, but only the boric acid taken progressively from its alcoholic combination by the soda of the titrated solution up to the moment when the polyatomic alcohol, completely free from its boric combination, remains inert, when the slightest excess of soda instantly produces the blue colour.-Journ. de Pharm. et de Chim., Series 6, vol. viii., No. 3.

CHEMICAL NEWS,
Dec. 2, 1898.

character. They somewhat resemble the corresponding shades given by apigenin, and, as the chief decomposition products of both colouring-matters are identical, it is probable that apigenin and vitexin are closely related.

Homovitexin, C16H160, or C18H1808, is present in the wood only in minute quantity. It crystallises in fine primrose-yellow needles, melts at 245-246°, and is distinguished from vitexin, which it otherwise resembles, by its ready solubility in alcohol. Fusion with alkali gives phloroglucinol and parahydroxybenzoic acid, and treat. ment with dilute nitric acid yields metadinitroparahydroxybenzoic acid. It dyes mordanted fabrics feebly.

The shades given by "puriri " with chromium and aluminium mordants are distinguished by their pure yellow tone, and may have some commercial utility.

131. "Cannabinol." By T. B. WOOD, M.A., W. T. N. SPIVEY, M.A., and T. H. Easterfield, M.A., Ph.D.

In former communications (Proc., 1898, xiv., 66, 153) a number of derivatives of cannabinol have been described; a detailed account of these is given in the present paper. The oily lactone (loc. cit., 153), prepared from nitrocannabinolactone (oxycannabin), is shown to be a metatolyl. butyrolactone, oxycannabin being the corresponding nitro derivative. By the oxidation of cannabinolactone, a lactonic acid is produced, which on fusion with potash yields isophthalic acid. Nitrocannabinolactonic acid is obtained by oxidising

Venetian sumach, the leaves of R. Cotinus, contains myricetin, and not quercetin as stated by Löwe (Zeit. Anal. Chem., 1874, xil., 127). The leaves of R. rhodan-oxycannabin either by dilute nitric acid in a sealed tube or by potassium permanganate. thema, the yellow cedar of New South Wales, contain quercetin and gallotannic acid. The stems of both plants by nitric acid are shown to be normal butyric (Dunstan The volatile fatty acids produced on oxidising cannabinol contain ficetin, and the leaves thus contain the more and Henry, Proc., 1898, xiv., 44), normal valeric, and highly oxidised colouring-matters, as quercetin and myri-normal caproic acids, valeric acid being formed in the cetin are considered to be hydroxy- and dihydroxy-fisetin largest amount. respectively. Other members of the Rhus family hitherto examined contain no fisetin in the stem. The Venetian sumach examined contained 16'7 per cent, and the R. rhodanthema leaves 9'5 per cent of tannin.

The leaves of Artocarpus integrifolia (Jackwood tree), A. incisa (bread fruit), and A. lakoocha are devoid of colouring-matter.

130.

66 Colouring-matters of the New Zealand Dyewood 'Puriri.'" By ARTHUR GEORGE PERKIN. "Puriri" (Vitex littoralis) is a large tree, growing in northern New Zealand, and chiefly used for building and similar purposes. Its tinctorial properties are little known. It contains two colouring-matters in the form of glucosides.

132. "Derivatives of Hesperitin." By A. G. PERKIN. Hesperitin is found as the glucoside hesperidin in the citron, bitter orange, and other fruits of the same class. With potassium hydrate solution at 100° it gives phloroglucinol and hesperitinic or hydroxymethoxycinnamic acid. It thus appears to have the constitution

OH C6H3(OMe) CH: CH CO-O·C6H3(OH)2 (Hoffmann, Ber., 1876, ix., 685; Tiemann and Will, Ber., 1881, xiv., 948). With alcoholic potassium and sodium acetates, hesperitin gives the compounds

(C16H1406)2,KC2H3O2, and (C16H1406)2, NaC2H3O2, which form colourless needles and decompose on treatment with boiling water, regenerating hesperitin. With sodium and potassium bicarbonates, sodium hesperitin, 32H27O12Na, and potassium hesperitin, C32H27O12K, are formula of hesperitin is thus C2H28012. obtained, crystallising in minute colourless plates. The

Vitexin, C15H1407 or C17H1608, the chief product, is a canary yellow crystalline powder, distinguished by its sparing solubility in most solvents. Owing to the diffi. culty of obtaining substitution products without decom position, its molecular weight is at present uncertain. Acetylvitexin, CH9O7Acs or C17H10O8Ac6, forms colour-needles, melts at 246-247°, and yields a diacetyl derivaless needles melting at 251-256°. On fusion with alkali, phloroglucinol, acetic and parahydroxybenzoic acids are formed, whilst boiling aqueous or alcoholic potash solutions give phloroglucinol and parahydroxyacetophenone. Further, the product of the ethylation of vitexin with boiling alcoholic potash yields paraethoxybenzaldehyde, paraethoxybenzoic acid, and a phloroglucinol derivative. Warm nitric acid (sp. gr, 1'54) forms metadinitropara hydroxybenzoic and picric acids, but when dilute acid is employed a sparingly soluble nitro-compound,—

C15H605(NO2)41

of unknown constitution, is also obtained in small quantity. This consists of small lemon-yellow needles, which dye mordanted calico ; it is converted by strong nitric acid into picric acid, and appears to be closely related to vitexin. With nitrobenzene it forms an addition product, CsH605(NO2)4,C6H,NO2, crystallising in orangecoloured needles which lose nitrobenzene at 150°, or by digestion with alcohol. Vitexin gives very pure yellow shades on calico mordanted with chromium and aluminium salts, but owing to its insolubility these are of a poor

Azobenzenehesperitin, C32H24O12(N2Ph)4, forms red tive, C32H22O12Ac2(N,Ph), crystallising in ochre needles six hydroxyl groups, and this view of its constitution is conmelting at 240-242°. Hesperitin should thus contain firmed by the formation of acetylhesperitin, C32H22O6Ac6, which crystallises in colourless needles melting at 127-129°.

by Tiemann and Will would thus be correct. Though If hesperitin were C16H1406, the constitution assigned not considered to be a polymeride of a substance of this formula, it must consist of two very similar groups linked together, as Hoffmann (loc. cit.) obtained from hesperitin a nearly quantitative yield of phloroglucinol and hesperitinic acid.

Research Fund.

A meeting of the Research Fund Committee will be held in December. Applications for grants, accompanied by full particulars, should be received by the Secretaries not later than December 5th. Forms of application can be obtained from the Assistant-Secretary, Chemical Society, Bualington House, W.

CHEMICAL NEWS.}

Dec. 2, 1898.

Chemical Society.-Banquet to Past-Presidents.

THE BANQUET TO PAST PRESIDENTS.

The Banquet to the Past Presidents who have been Fellows for half a century:

273

as if they were present with us, as you will understand from the few illustrations I will give you of the sympathetic language they use. Professor Friedel writes:I should have been happy to associate myself with the Chemical Society in doing honour to these veterans of science. I have the honour to be the friend of most of them, and the beneficent action they have exerted on Chemical Science cannot be esteemed too highly. They which exists in any country. form the finest phalanx of the Fathers of our science With these sentiments, you will understand the liveliness of my regret to be able to take part from afar and in spirit only in the honour paid them.' We have also received congratulations from learned societies both in Germany and Russia. At a meeting of the Russian Chemical Society the following resolution was passed: That the Society avail itself of the exceptional opportunity of being able to congratulate land, Professor Odling, Sir F. A. Abel, Dr. A. W. conjointly Sir Joseph Henry Gilbert, Sir Edward Frank. Williamson, and Dr. J. H. Gladstone, whose distinguished services during half a century stand out as a model for all investigators in chemical science, and also express the wish to see the further results of their labours in the annals of science for many years to come.' The telegram from the German Chemical Society strikes me as very happy. Dr. Liebermann says:-The sister Society sends both Jubilee congratulations and greetings to the Jubilee celebration of the Presidents of the Chemical Society, Gilbert, Frankland, Odling, Abel, Williamson, and Gladstone.' This shows, I think, that our Continental brethren appreciate the honour we desire to offer these distinguished men; and we need not be surprised that there is something more throughout these communications than mere cosmopolitanism in science. They breathe the spirit of friendly regard, of reverence, and even of love towards men who have done so much to advance the common cause of our science. How impossible it seems to sum up in any short speech the work that these men have done! If I attempted to classify them, I should say that if we regarded them as twos and twos they would not group well together, but if we take three at a time they bear somewhat close relations one towards another. I would say that Gilbert and Abel and Gladstone are monarchs of dependent kingdoms, whereas Frankland and Odling and Williamson are a triumvirate that have legislated towards the imperial side of chemical science.

"I have now the honour to propose to you what you must all regard as a toast to which I cannot possibly do justice, the health of six of the most distinguished Past Presidents of the Chemical Society who for more than half a century have been members of that body. It is admitted on all hands that Chemical Science has added enormously to the resources and power of mankind, and that its successful cultivation involves the exercise of every faculty of the human mind. We have here six illustrious examples of successful scientific culture, and, I would add, of bracing moral influence,-men whose one idea it has been, with steady aim and vigilant eye, to labour on with that sole incentive of scientific work, the triumphant hope of making an advance. These men have laboured for half a century in our interests, and they have added enormously to our knowledge of the science. It is almost impossible to realise the variety of the work they have done; the width of it is something appalling; when I tell you that, amongst them, they have recorded upwards of four hundred and fifty separate communica. tions-how many there are that have not been recorded I cannot say and that among these four hundred and fifty there are many papers of the highest importance, I "The work of Gilbert, as we know, was early differenam sure you will agree with me that they have exercised tiated into that most complex and mysterious study, the a remarkable influence on the development of our science. study of organic life. For the last fifty years he has deIt was well that the Chemical Society of London-the voted his attention to the physiology of plant life in every oldest Chemical Society in the world-should inaugurate phase of its development. With a skill that has been this banquet. The Council felt that probably they might unprecedented, he has recorded from year to year the never again have the opportunity of calling together such variations in the growth of every kind of nutritious plant. a distinguished body of men as they have the honour of He has examined into the meteorological conditions, the offering this banquet to to-night. We are still able to go variations of climate, of soil and of mineral agents, of back to a man, who sits on my right hand, who worked in drainage, and of every conceivable thing affecting the the laboratory of Thomas Thomson, who has seen Dalton production and development of plant growth. These and the beginning of the Atomic Theory, probably the memoirs are admitted throughout the world to be unique most wonderful of all the laws of Nature which man has in their importance. Wherever the chemist or the physi ever been permitted to decipher. That being the case, ologist, the statistician or the economist, has to deal with the way in which the idea has been received by all the these problems, he must turn to the results of the chemists of this country is apparent from the number of Rothamsted experiments in order to understand the po men of talent and the variety of classes here to-night.sition of the science of our time. These results will be But beyond that, the sympathy of every chemist in the for ever memorable: they are unique and characteristic of world is with us to-night at this banquet. The large the indomitable perseverance and energy of our venerated number of congratulatory telegrams and communications President, Sir Henry Gilbert. that we have received to-day from every country where the science of chemistry is cultivated, will give some idea of the appreciation with which this banquet is regarded throughout the whole civilised world. We have received communications from France, Holland, Belgium, Germany, Sweden, Russia, Austria, the United States, and other countries. It is unnecessary for me to read every name, for every man identified with the progress of che. mistry in every civilised country has responded by sending some form of congratulation. In every case the write

"The next among them, Sir Edward Frankland, I should characterise as one of the most remarkable experi mentalists of this or any other age. He has been gifted with an absolutely unique faculty for experimental work and observation. The breadth and variety of his work is positively astounding. From early times devoted to the study of Organic Chemistry, he has branched out not only into Mineral Chemistry, but every form almost of applied industry. His early work on the organo-metallic bodies, so fertile in the way of future development, will be ever

274

Chemical Society.-Banquet to Past-Presidents.

memorable. These bodies have been the means of adding, to our knowledge of synthetical substances produced in the laboratory in a way that no other agencies have operated. Along with this work, he has executed investiga tions bearing on flame and the character of the light emitted by various bodies, and on a large number of questions connected with sanitary chemistry. His great work on the water supply of the United Kingdom, on the sewage question, and other industrial problems, are generally acknowledged to be of great value and importance. Whatever work he has done is marked with the stamp of genius.

"The work of Odling has been an essential factor in the development of modern chemistry. It is characterised by precise and clear ideas, and an almost forensic ability for putting things in a straight, concise, and unembarrassing manner. His early labours in advancing the development of the newer chemistry deserve our warm gratitude, and his many published works and addresses on organic and inorganic chemistry, together with his translation of the work of Laurent, have all been of material service in diffusing a knowledge of our science. The papers he has contributed on Chemical Notation and on the question of types all display a marvellous precision as well as elegance of thought. Every one must admit the debt of gratitude we owe him for his iconoclastic labours in clearing out old and vague notions, and for the courageous manner in which he supported the newer ideas of his time. "In the case of Abel, we have again a man who, at an early time, had his career differentiated for him. A distinguished student of Hofmann's, his early work was directed to organic chemistry, but he soon diverged into other channels, directing his attention to problems bearing on the chemistry of naval and military matters. We all know his splendid work on gunpowder, guncotton, detonation, and the whole field of explosive agents. Whether in connection with accidents in mines, from petroleum, or from flour, dust, or other agency, Abel has been a marvellous experimenter in the whole field of explosive chemistry. While engaged in these investigations in applied chemistry, however, he was adding to the ad. vancement of pure science by the light which his researches threw upon many questions of chemical theory and by the stimulus thus given to further inquiry. He has had the great satisfaction of living through the age of gunpowder. That body had been the recognised explosive for many hundred years, and I have no doubt that when he commenced his investigations with Noble on gunpowder he never dreamt that he would live to see the day when he would clear out that smoky material and replace it before he left the War Office by a powder that is smokeless. I need hardly tell you that he has also added to our debt of gratitude by the personal services he has rendered to many learned societies.

I come now to Williamson. The work of Williamson proclaims him a truly philosophic chemist. He has had probably the greatest satisfaction of any one I know. He cleared up one of the most intricate and recondite of chemical reactions, that with which we are familiar as etherification, and in so doing he struck at the very root of the chemical problems connected with atomic and molecular weights, and realised and cleared up for ever those mysterious modes of explanation which were undoubtedly faulty and insecure. Before his time, men as great as Berzelius, Mitscherlich, and Graham, believed in that contact or catalytic action which in my early days bridged over the period between the old and the new, and was generally introduced when no other explanation was forthcoming. Williamson cleared all that away; but the discovery of these ethereal nepenthes did not act in chemistry as they would have done physiologically; they did not produce a soporific effect. They struck at the foundations of our science, and it is to his great credit that he originated advanced ideas, not only as to etherification, but as to molecular weights, type formulæ, and so forth. In fact the chemistry of our time would not be the che

{OHEMICAL NEWS,

Dec. 2, 1898.

mistry of our time but for the work of Williamson. I would further add that he was one of the earliest to introduce the idea of dynamics into chemical science. His suggestion of the dynamical theory of the voltaic battery and of dynamic mobility in apparent stability has been exceedingly fruitful since his time; and if we add to them that most important and original idea of Frankland's, the saturation power of the elementary bodies, we have all the agencies of our modern scientific notions. One other debt of gratitude we owe to Williamson, and that is the interest he took in introducing into this country abstracts of all the important scientific memoirs published on the Continent, It is to him we owe those valuable abstracts which have been printed for many years in the Chemical Society's Journal, and have done so much for the advancement of our science.

"Gladstone, on the other hand, represents a type somewhat different from that of any of the others that I have mentioned. He belongs to a characteristically English variety of men who have studied science for its own sake. Like Spottiswoode, De la Rue, and Joule, he has not been a professional scientist in the ordinary sense, but has worked out his long and brilliant scientific career as a labour of patient love. Furthermore, he has created an entirely new department-that which is in modern times regarded as physical chemistry, of which we have here tonight some distinguished representatives. For half a century he has worked on this side of chemistry, for his early investigation of the spectrum of the atmosphere was one of marvellous suggestiveness. He found that the spectrum of Fraunhofer varied at sunset and at sunrise from that at mid-day, and showed that a large number of those absorption lines must originate in the earth's atmosphere. That discovery stimulated further inquiry as to the substance that could produce these lines so characteristic of the solar atmosphere; and later experimenters have found it in the vapour of water and in oxygen. Gladstone's greatest merit, however, lies undoubtedly in his optical researches on the atomic refractions and dispersions of the elements. He has determined the optical constants of hundreds of bodies, and has thus stimulated inquiry in that borderland between physics and chemistry which is so much cultivated in the present day, and the pursuit of which has added so much to our knowledge. He has also contributed largely to miscellaneous inquiries, especially those connected with various voltaic batteries, and other questions conducive to the study of both organic and inorganic chemistry.

"This is but a brief epitome of the work of these great men. It would be, as I have said, hopeless for me to attempt to sum up all their individual labours. We can only skim the surface of the ocean of truth in which they have navigated so well and so successfully. But I will say this: that as experimentalists we are not likely to see their like again, and it is impossible to imagine a more extraordinary galaxy of chemical talent than these six Past-Presidents represent. They have rendered the science of chemistry more glorious for those who strive to follow; and the brilliant record of their discoveries can never be eliminated from the history of our Science. In the future, posterity will regard them as the most gifted and illustrious of the English chemists of the Victorian epoch. My Lords and Gentlemen, I give you the health of our venerated Past-Presidents, Sir Henry Gilbert, Sir Edward Frankland, Professor Odling, Sir Frederick Abel, Professor Williamson, and Dr. Gladstone."

Sir J. HENRY GILBERT-"After the extremely flattering and eloquent terms in which our President has referred to the work of the six Past-Presidents of the Society who are so highly honoured to-night, it is surely a difficult task to say anything in response. I feel that any words of mine would be entirely inadequate; and I must, I think, fall back on what I was intending to say, and give a little personal history of the early times of the Society. You are aware, most of you, that I am to-night in the position of the senior of the Past-Presidents, in consequence of