ACTION OF FLUORINE UPON A FEW ORGANIC COMPOUNDS.
Chloroform.—When chloroform is saturated with fluorine, and subsequently boiled, carbon tetrafluoride, hydrofluoric acid and chlorine are evolved. If a drop of chloroform is agitated in a glass tube with excess of fluorine, a violent explosion suddenly occurs, accompanied by a flash of flame, and the tube is shattered to pieces. The reaction is very lively when fluorine is evolved in the midst of a quantity of chloroform, a persistent flame burns beneath the surface of the liquid, carbon is deposited, and fluorides of hydrogen and carbon are evolved together with chlorine.
Methyl chloride is decomposed by fluorine, even at -23°, with production of a yellow flame, deposition of carbon, and liberation of fluorides of hydrogen and carbon and free chlorine. With the vapor of methyl chloride, as pointed out in the description of the electrolysis, violent explosions occur.
Ethyl alcohol vapor at once takes fire in fluorine gas, and the liquid is decomposed with explosive violence without deposition of carbon. Aldehyde is formed to a considerable extent during the reaction.
Acetic acid and benzene are both decomposed with violence, their cold vapors burn in fluorine, and when the latter is bubbled through the liquids themselves, flashes of flame, and often most dangerous explosions, occur. In the case of benzene, carbon is deposited, and with both liquids fluorides of hydrogen and carbon are evolved. Aniline likewise takes fire in fluorine, and deposits a large quantity of carbon, which, however, if the fluorine is in excess, burns away completely to carbon tetrafluoride.
Such are the main outlines of these later researches of M. Moissan, and they cannot fail to impress those who read them with the prodigious nature of the forces associated with those minutest of entities, the chemical atoms, as exhibited at their maximum, in so far as our knowledge at present goes, in the case of the element fluorine.—Nature.
APPARATUS FOR THE ESTIMATION OF FAT IN MILK.
By E. MOLISABI.
The author, after criticising the various methods for estimating fat in milk which have been proposed from time to time, agrees with Stokes (Analyst, 1885, p. 48), Eustace Hill (Analyst, 1891, p. 67), and Bondzynsky (Landwirth Jahrb. der Schweiz, 1889), that the method of Werner Schmid is the simplest, most rapid, and convenient hitherto introduced. The conditions tending to inaccuracy are: The employment of ether containing alcohol; boiling the mixture of milk and acid too long, when a caramel-like body is formed, soluble in ether; the difficulty of reading off the volume of ether left in the tube, owing to the gradations of the instrument being obscured by the flocculent layer of casein; when only a portion of the ether is used, fat may be left behind in the acid mixture, as shown by Allen (Chem. Zeit., 1891, p. 331). The author believes that by the invention of the simple apparatus represented in the accompanying figure, he has rendered the process both accurate and convenient. This consists of a flask B of about 75 c.c. capacity, which has a glass tap fused on, with two capillary tubes attached, the one passing upward, the other downward. The neck of flask B is ground into the neck of flask A, which holds about 90 c.c. Either of the flasks can be placed in communication with the external air by the opening a. The ether must be previously washed with one or two tenths of its volume of water, to remove traces of alcohol. The operation is performed as follows: 10 c.c. of well mixed milk are weighed in (or measured into) flask A, 10 c.c. of hydrochloric acid added, and the mixture heated to boiling on an asbestos sheet. The boiling must not exceed a minute and a half, the fluid being shaken from time to time, and not allowed to become of a deeper color than a dark brown [not black]. The flask is cooled, and 25 c.c. of ether added. The two flasks are connected as shown in the figure, the tap closed, and the whole shaken for a few minutes, the flask being vented two or three times by the opening a. The apparatus is now inverted, allowed to stand five or six minutes, the tap turned, and the dark acid liquid drawn off into flask B. By a little shaking of the ether the whole of the acid liquid may be easily got into the lower flask. The apparatus is again inverted, then separated, 10 c.c. of ether are introduced into the flask B, the tap closed, and the fluids well shaken. When the ether layer is distinct, the acid liquor is run off, and the ether solution transferred to A. The whole of the ether solution is washed in the apparatus two or three times with a little water, the flask A removed to the water bath, the ether driven off, the last traces of ether and water being removed by placing the flask in a drying oven heated from 107 to 110° C., where it must remain at least twenty minutes. The usual cooling in the exsiccator and weighing concludes the operation. Examples are given showing its concordance with the Adams and other recognized processes. Sour milk, which must be weighed in the flask, can be conveniently analyzed; also cream, using 5 grammes cream and 10 c.c. hydrochloric acid. (Berichte Deutsch. Chem. Gesell., 24, p. 2204).—The Analyst.
AMERICAN ASSOCIATION—NINTH ANNUAL REPORT OF THE COMMITTEE ON INDEXING CHEMICAL LITERATURE.[1]
The Committee on Indexing Chemical Literature respectfully presents to the Chemical Section its ninth annual report.
Since our last meeting the following bibliographies have been printed:
1. A Bibliography of Geometrical Isomerism. Accompanying an address on this subject to the Chemical Section of the American Association for the Advancement of Science at Indianapolis, August, 1890, by Professor Robert B. Warder, Vice President. Proceedings A.A.A.S., vol. xxxix. Salem, 1890. 8vo.
2. A Bibliography of the Chemical Influence of Light, by Alfred Tuckerman. Smithsonian Miscellaneous Collections No. 785. Washington, D.C., 1891. Pp. 22. 8vo.
3. A Bibliography of Analytical Chemistry for the year 1890, by H. Carrington Bolton. J. Anal. Appl. Chem., v., No. 3. March, 1891.
We chronicle the publication of the following important bibliography:
4. A Guide to the Literature of Sugar. A book of reference for chemists, botanists, librarians, manufacturers and planters, with comprehensive subject index. By H. Ling Roth. London: Kegan Paul, Trench, Trubner & Co. Limited. 1890. 8vo. Pp xvi-159.
This work contains more than 1,200 titles of books, pamphlets, and papers relating to sugar. Many of the titles are supplemented with brief abstracts. The alphabetical author catalogue is followed by a chronological table and an analytical subject index. The compilation extends to the beginning of the year 1885, and the author promises a supplement and possibly an annual guide.
The ambitious work is useful but very incomplete. It does not include glucose. The author gives a list of fifteen periodicals devoted to sugar, and omits exactly fifteen more recorded in Bolton's Catalogue of Scientific and Technical Periodicals (1665-1882). Angelo Sala's Saccharologia is not named, though mentioned in Roscoe and Schorlemmer and elsewhere.
Notwithstanding some blemishes, this work is indispensable to chemists desirous of becoming familiar with the literature of sugar. It is to be hoped that a second edition brought down to date may be issued by the author.
5. A Bibliography of Ptomaines accompanies Professor Victor C. Vaughan's work, Ptomaines and Leucomaines. Philadelphia, 1888. (Pages 296-814.) 8vo.
Chemists will hail with pleasure the announcement that a new dictionary of solubilities is in progress by a competent hand. Professor Arthur M. Comey, of Tufts College, College Hill, Mass., writes that the work he has undertaken will be as complete as possible. "The very old matter which forms so large a part of Storer's Dictionary will be referred to, and in important cases fully given. Abbreviations will be freely used and formulæ will be given instead of the chemical names of substances, in the body of the book. This is found to be absolutely necessary in order to bring the work into a convenient size for use ..., The arrangement will be strictly alphabetical. References to original papers will be given in all cases ..."
Professor Comey estimates his work will contain over 70,000 entries, and will make a volume of 1,500-1,700 pages.
The following letter from Mr. Howard L. Prince, Librarian of the United States Patent Office, explains itself:
WASHINGTON, D.C., February 11, 1891
Dr. H Carrington Bolton.
University Club, New York, N.Y.:DEAR SIR—In response to your request I take pleasure in giving you the following information regarding the past accomplishments and plans for the future of the Scientific Library in the matter of technological indexing.
The work of indexing periodicals has been carried on in the library for some years in a somewhat desultory fashion, taking up one journal after another, the object being, apparently, more to supply clerks with work than the pursuance of any well defined plan. However, one important work has been substantially completed, viz., a general index to the whole set of the SCIENTIFIC AMERICAN and SUPPLEMENT from 1846 to date.
It is unnecessary for me to point out to you the importance of this work, embracing a collection which has held the leading place in the line of general information on invention and progress, the labor of compiling which has been so formidable that no movement in that direction has been attempted by the publishers except in regard to the SUPPLEMENT only, and that very imperfectly. This index embraces now 184,600 cards, not punched, and at present stored in shallow drawers and fastened by rubber bands, and of course they are at present unavailable for use. There is little prospect of printing this index, and I have been endeavoring for some time to throw the index open to the public by punching the cards and fastening them with guard rods, but as yet have made no perceptible impression upon the authorities, although the expense of preparation would be only about $70.
There has also been completed an index to the English journal Engineering, comprising 84,000 cards, from the beginning to date.
An index to Dingler's Polytechnisches Journal was also commenced as long ago as 1878, carried on for six or seven years and then dropped. I hope, however, at no remote date, to bring this forward to the present time.
On taking charge of the library I was at once impressed with the immense value of the periodical literature on our shelves and the great importance of making it more readily accessible, and have had in contemplation for some time the beginning of a card index to all our periodicals on the same general plan as that of Rieth's Repertorium. I have, however, been unable to obtain sufficient force to cover the whole ground, but have selected about one hundred and fifty journals, notably those upon the subjects of chemistry, electricity and engineering, both in English and foreign languages, the indexing of which has been in progress since the first of January. This number includes substantially all the valuable material in our possession in the English language, not only journals, but transactions of societies, all the electrical journals and nearly all the chemical in foreign languages. This index will be kept open to the public as soon as sufficient material has accumulated. In general plan it will be alphabetical, following nearly the arrangement of the periodical portion of the surgeon general's catalogue. I shall depart from the strictly alphabetical plan sufficiently to group under such important subjects as chemistry, electricity, engineering, railroads, etc., all the subdivisions of the art, so that the electrical investigator, for instance, will not be obliged to travel from one end of the alphabet to the other to find the divisions of generators, conductors, dynamos, telephones, telegraphs, etc., and in the grouping of the classes of applied science the office classification of inventions will, as a rule, be adhered to, the subdivisions being, of course, arranged in alphabetical order under their general head and the title of the several articles also arranged alphabetically by authors or principal words.
With many thanks for the kind interest and valuable information afforded me, I remain, very truly yours,
HOWARD L. PRINCE,
Librarian Scientific Library.
The committee much prefers to record completed work than to mention projects, as the latter sometimes fail. It is satisfactory, however, to announce that the indefatigable indexer, Dr. Alfred Tuckerman, is engaged on an extensive Bibliography of Mineral Waters. The chairman of the committee expects to complete the MS. of a Select Bibliography of Chemistry during the year, visiting the chief libraries of Europe for the purpose this summer.
H. CARRINGTON BOLTON, Chairman.
F.W. CLARKE,
ALBERT R. LEEDS,
ALEXIS A. JULIEN,
JOHN W. LANGLEY,
ALBERT B. PRESCOTT.
[Dr. Alfred Tuckerman was added to the committee at the Washington meeting to fill a vacancy.]
From advance proof sheets of the Proceedings of the American Association for the Advancement of Science; Washington meeting, 1891.
THE FRENCH WINE LAW.
The French wine law (Journ. Officiel, July 11, 1891) includes the following provisions:
Sect. 1. The product of fermentation of the husks of grapes from which the must has been extracted with water, with or without the addition of sugar, or mixed with wine in whatever proportion, may only be sold, or offered for sale, under the name of husk wine or sugared wine.
Sect. 2. The addition of the following substances to wine, husk wine, sugared wine, or raisin wine will be considered an adulteration:
1. Coloring matters of all descriptions.
2. Sulphuric, nitric, hydrochloric, salicylic, boric acid, or similar substances.
3. Sodium chloride beyond one gramme per liter.
Sect. 3. The sale of plastered wines, containing more than two grammes of potassium, or sodium sulphate, is prohibited.
Offenders are subject to a fine of 16 to 500 francs, or to imprisonment from six days to three months, according to circumstances.
Barrels or vessels containing plastered wine must have affixed a notice to that effect in large letters, and the books, invoices, and bills of lading must likewise bear such notice.
THE ALLOTROPIC CONDITIONS OF SILVER.
M. Berthelot recently called the attention of the Academy (Paris) to the memoirs of Carey Lea on the allotropic states of silver, and exhibited specimens of the color of gold and others of a purple color sent him by the author. He explained the importance of these results, which remind us of the work of the ancient alchemists, but he reserved the question whether these substances are really isomeric states of silver or complex and condensed compounds, sharing the properties of the element which constituted the principal mass (97-98 per cent.), conformably to the facts known in the history of the various carbons, of the derivatives of red phosphorus, and especially of the varieties of iron and steel. Between these condensed compounds and the pure elements the continuous transition of the physical and chemical properties is often effected by insensible degrees, by a mixture of definite compounds.
The following letter appears in a recent number of the Chemical News.
Sir: In a recently published lecture, Mr. Meldola seems to call in question the existence of allotropic silver. This opinion does not appear, however, to be based on any adequate study of the subject, but to be somewhat conjectural in its nature. No experimental support of any sort is given, and the only argument offered (if such it can be called) is that this altered form of silver is analogous to that of metals whose properties have been greatly changed by being alloyed with small quantities of other metals. Does, then, Mr. Meldola suppose that a silver alloy can be formed by precipitating silver in the presence of another metal from an aqueous solution, or that one can argue from alloys, which are solutions, to molecular compounds or lakes? Moreover, he has overlooked the fact that allotropic silver can be obtained in the absence of any metal with which silver is capable of combining, as in the case of its formation by the action of soda and dextrine. Silver cannot be alloyed with sodium.
Mr. Meldola cites Prange as having shown that allotropic silver obtained with the aid of ferrous citrate contains traces of iron, a fact which was published by me several years earlier, with an analytical determination of the amount of iron found. Mr. Prange repeated and confirmed this fact of the presence of iron (in this particular case), and my other observations generally, and was fully convinced of the existence of both soluble and insoluble allotropic silver. Mr. Meldola's quotation of Mr. Prange would not convey this impression to the reader.
Of the many forms of allotropic silver, two of the best marked are the blue and the yellow.
Blue allotropic silver is formed in many reactions with the aid of many wholly different reagents. To suppose that each of these many substances is capable of uniting in minute quantity with silver to produce in all cases an identical result, the same product with identical color and properties, would be an absurdity.
Gold-colored allotropic silver in thin films is converted by the slightest pressure to normal silver. A glass rod drawn over it with a gentle pressure leaves a gray line behind it of ordinary silver. If the film is then plunged into solution of potassium ferricyanide it becomes red or blue, while the lines traced show by their different reaction that they consist of ordinary silver. Heat, electricity, and contact with strong acids produce a similar change to ordinary gray silver.
These reactions afford the clearest proof that the silver is in an allotropic form. To account for them on suppositions like Mr. Meldola's would involve an exceedingly forced interpretation, such as no one who carefully repeated my work could possibly entertain.
I am, etc.,
M. CAREY LEA.
Philadelphia, October 22, 1891.