Imágenes de páginas
PDF
EPUB

CHEMISTRY.

The Chemical Society's Faraday Lecture.-On Thursday, May 30, Professor Cannizzaro, of Palermo, delivered the "Faraday Lecture" before a large audience, including a number of ladies. The Lecture Theatre of the Royal Institution had been kindly lent to the Chemical Society for this purpose, and the learned Professor's discourse was entitled "Considérations sur quelques Points de l'Enseignement Théorique de la Chemie." On the following Friday a dinner was given to the Professor, at which about 150 were present, including the Italian ambassador and the Right Hon. the Chancellor of the Exchequer. We think it is a pity that some arrangement is not made by which the lecturer could address his audience in English, for we are certain that very few of them apprehend French sufficiently well to take in even the substance of the lecture.

Chemical Analysis of the Meteoric Rain in Sicily of March 9, 10, and 11. -M. O. Silvestri has an important memoir on this subject in the "Comptes Rendus," April 9, 1872. This memoir contains the results of the researches made on rain-water along with which fell a kind of sand; the water, having been filtered, was found to be colourless and free from smell, but exhibited a saline taste; it was neutral to test-paper; hardness, 17·5 degrees (ordinary rain-water, 1 degree). By long-continued boiling, it gave off 19 c.c. of gas, consisting of: nitrogen, 83-959 per cent.; oxygen, 13·070; CO2, 2·971. On being evaporated to dryness, this water was found to contain, in 1,000 parts: bicarbonates of lime, 0·129; of magnesia, 0-035; of iron, traces; sulphate of lime, 0·041; chloride of potassium, traces; sulphate of soda, 0.009; chloride of sodium, trace; organic matter, 0-063. The sand, very finely pulverised and dust-like, has a sp. gr. -2·5258, and contains, in 100 parts: clay, 75-08; carbonate of lime, 11·65; organic matter, 13 10.

Dr. Hoffmann on Phosphuretted Hydrogen.-On Dr. Hoffmann's recent visit to this country, he went to the Chemical Society as a matter of course. On April 18 he there experimentally exhibited the formation of phosphuretted hydrogen by the action of water on iodide of phosphonium, and the decomposition of iodide of ethyl-phosphonium by water, liberating the ethyl-phosphine, E,HN, which has the characteristic odour of the phosphorus bases. He also explained Baeyer's method of preparing iodide of phosphonium on the large scale by the action of water on iodide of phosphorus, stating that it was necessary to employ a large excess of phosphorus, three or four times the theoretical, since much of it is converted into the amorphous state, and thereby rendered inactive.

Chloride of Sodium in Liebig's Extract of Meat.-In the "Annalen der Chimie" for May, Baron Justus von Liebig has written a paper with the view to refute the allegation made by a Dr. Godefroy, who appears to have published, in an Austrian scientific paper, a statement to the effect that Liebig's extract of meat should contain 2 per cent, of chloride of sodium, purposely added as a fraud. The author refers Dr. Godefroy to his (Liebig's) essays, published in the "Annalen" twenty years ago, "On the Constituents of the Fluids contained in Meat," and emphatically denies that at Fray Bentos, where the extract of meat is made, any common salt is added to it. Chloride of potassium is largely contained in the extract.

Determining Carbonic Acid in Sea-water.-Professor Himly, at the meeting of the Chemical Society, April 18, after pointing out the difficulties which beset the determination of carbonic acid in sea-water-Jacobsen having shown that the whole of the gas present is not given off by boiling, either in vacuo or under the ordinary pressure at 100°, even when a current of air is passed through the liquid-said, however, that the whole of the carbonic acid could be readily estimated by adding baryta water or barium nitrate, ammonium nitrate, and ammonia, to a measured quantity of the sea-water, thus obtaining the whole of the carbonic acid in the precipitate. After the supernatant liquid had been removed, the carbonic acid might be estimated in the precipitate. In order to collect sea-water for the determination of the carbonic acid at great depths, and consequently under great pressures, it was necessary to sink a cylinder open at both ends to the place where the water was to be collected, and then to securely close it there. The apparatus for that purpose, closed by valves, had been found to be very defective; but he had employed one which answered admirably, consisting of a cylinder furnished with a large stop-cock at each end. When this cylinder had been sunk to the required depth, the stop-cocks were closed by powerful springs released at the proper moment by means of an electro-magnet set in action in the usual way. (See also "Chemical News.")

A New Organic Pigment has been obtained from a spot above the eyes of the moor-cock. It is called Tetronerythrin, and has been described by Dr. Wurm in "Poggendorff's Annalen." It seems ["Chemical News"] that a statement was made in the "Wiener Jagdzeitung" to the effect that the red warty spot met with above the eyes of the mountain-cock and moorcock (Tetrao tetrix), when rubbed with a white handkerchief, imparted thereto a beautiful red colour. The author was inclined to disbelieve this, and accordingly made some microscopical and microchemical researches on this subject, the result being that he discovered a pigment which he terms Tetronerythrin (from Tetraon and erythros, mountain-cock red). A very small quantity of this pigment, which is soluble in chloroform, was sent by the author to Dr. J. von Liebig, who states that it is a peculiar substance which has nothing in common with the colouring matter of the blood; it is soluble in ether and sulphide of carbon, not soluble in cold caustic alkaline solutions, and soluble in hot nitric acid, but decomposed simultaneously, leaving a waxy residue.

How to Know Fruit-wine from Grape-wine.-According to Dr. F. Vorwerk ["Neues Jahrbuch für Pharmacie"], the phosphoric acid present in genuine grape-wine is combined with magnesia, while in fruit-wines it is present in combination with lime. The simple addition, therefore, of ammonia (1 part to 9 parts of wine), will produce in genuine wine, after twelve hours' standing, the well-known precipitate of ammonio-phosphate of magnesia.

1r. Letheby and Dr. Frankland on Water-analysis.-The editor of the "Chemical News" has quite recently given a leading article on this important subject. Referring to the controversy which has come up upon the matter, he states that if it had arisen in France there would have been a commission of the Academy to report on it. In this country we manage things differently, and resolve questions of this description after our own

fashion, and we have to collect the testimony of competent scientific men who live and work in isolation. Mr. Way, who was formerly on the Rivers' Commission, has published his judgment on this question in a report on the analysis of a sample of water. It is to the effect that he uses and has confidence in the rival process of Wanklyn and his colleagues, which, it is admitted, gives results in opposition to Dr. Frankland's. Dr. Angus Smith, who, as our readers possibly know, has been for some time engaged in a very important investigation of the organic matter existing in the atmosphere, has also given in his adhesion to the other process, which he employs in his researches. The late Dr. W. A. Miller rejected Dr. Frankland's process and employed Mr. Wanklyn's in his later investigations, undertaken for the medical department of the Privy Council. Dr. Voelcker, chemist to the Royal Agricultural Society, rejects Dr. Frankland's process and adopts the other. Dr. Letheby has often expressed a like opinion. Indeed, says the writer in conclusion, we scarcely know a single chemist of reputation who approves of Dr. Frankland's water-analysis !!

The asserted Alkalinity of Carbonate of Lime.—Mr. William Skey, Government Analyst, New Zealand, re-asserts the alkalinity of the above. He says, in a paper of his which appeared in the second volume of the "Transactions of the Wellington Philosophical Society, that he asserted the alkalinity of carbonate of lime, but the correctness of this assertion having been disputed by Mr. Charles R. C. Tichborne, F.C.S., M.R.I.A., &c., of the Laboratory of the Apothecaries' Hall, Ireland, in a communication to the editor of the "Chemical News" (vol. xxii. p. 150), he has re-investigated this subject and extended his researches upon it, by which he has arrived at results corroborative of the correctness of his statement, and which show, besides, that a large number of salts hitherto maintained to be neutral, or respecting which nothing has been affirmed, are in reality alkaline. This is important, for it may be regarded as conclusive so far as Mr. Skey's researches are concerned.-Vide "Chemical News," March 28.

The new Hydrocarbon: Abietene.-Mr. W. Wenzell, who writes in the “American Journal of Pharmacy," March, 1872, says that this hydrocarbon is the product of distillation of the terebinthinate exudation of a coniferous tree indigenous to California, viz., the Pinus sabiniana, a tree met with in the dry sides of the foot-hills of the Sierra Nevada mountains, and locally known as the nut-pine or digger pine, owing to the edible quality of its fruit. A gum resin, or rather balsam, is obtained from this tree by incisions made in its wood, and the balsam submitted to distillation almost immediately after having been collected, owing to the great volatility of the hydrocarbon (or essential oil, because abietene really stands in the same relation to the balsam alluded to as oil of turpentine stands to the exudation derived from other Pinus species). The crude oil, as usually met with for sale at San Francisco, is a colcurless limpid fluid, requiring only to be redistilled to obtain it quite pure. The commercial article is used under different names-abietine, erasine, theoline, &c.—for the removal of grease and paint from clothing and woven fabrics, and likewise as an efficient substitute for petroleum-benzine. The ultimate composition of abietene is not stated, but the author points out at some length the differences existing between abietene and terebene (oil of turpentine).

Influence of Pressure in producing Chemical Change.-An important paper on this subject has been read before the Chemical Society, May, 16, by Mr. H. T. Brown. In his investigation the author found that during the alcoholic fermentation of grape juice or malt wort, besides carbonic anhydride, that nitrogen, hydrogen, a hydrocarbon of the paraffin group, and sometimes nitric oxide, are evolved; moreover, the proportion of the gases unabsorbed by potassium hydrate is largely increased when the operation is carried on under diminished pressure. At the ordinary pressure by far the larger proportion of these gases is nitrogen (70 to 90 per cent), but under diminished pressure, 400 to 450 m.m., the hydrogen preponderates (60 to 90 per cent). Nitrogen, however, does not occur when the solutions contain no albumenoids, even if ammonium salts are present in considerable quantity. The increase of the proportion of hydrogen, resulting from diminution of the pressure, is accompanied by formation of a comparatively large amount of acetic acid and aldehyde, so that it would seem that water is decomposed during the alcoholic fermentation, and that this result is facilitated by the diminution of the pressure. The presence of nitric oxide in the evolved gases was found to be due to the reduction of nitrates originally present in the solutions.

Fearful Adulteration of Whisky in Ireland.—At a recent meeting of the Chemico-Agricultural Society at Belfast, under the presidency of Dr. Knox, late Poor Law Inspector, the subject of whisky adulteration was brought under consideration by Dr. Hodges, Professor in Queen's College, Belfast, who exhibited a specimen of that liquid brought to him by two men who had been physically incapacitated by drinking a small portion of it in a public-house. He found, on analys, that it contained a large amount of naphtha. He had also discovered that ingredients of even a more deleterious character were used in the process of adulteration-mixtures containing sulphate of copper (blue stone), cayenne pepper, sulphuric acid (vitriol), and a little spirits of wine. One specimen submitted to Dr. Hodges by a number of provision-cutters and curers, was composed of naphtha and a slight colouring of whisky. The men who had imbibed a small quantity of it were affected with serious symptoms; and this, said Dr. Hodges, was a fair specimen of the drink sold in low-class public-houses. The trade in this noxious compound is carried on with impunity, no local authority in Belfast or in the Province of Ulster caring to interfere with it.

A Substitute for Soda in washing Linen.-This, which appears to be extensively used abroad, will, we doubt not, prove of great service if introduced into the English laundry. It is described by Dr. Quesneville, in the Moniteur scientifique Quesneville (March). The very common use, says Dr. Quesneville, especially in England, of soda for washing linen is very injurious to the tissue, and moreover has the effect of yellowing it in the long run. The author states that in Germany and Belgium the following mixture is now extensively and beneficially used:-2 lbs. of soap are dissolved in 25 litres (5.5 gallons) of water, as hot as the hand can bear it; there are next added to this fluid three large-sized tablespoonfuls of liquid ammonia and one spoonful of best oil of turpentine. These fluids are incorporated rapidly by means of beating the soap-suds and other fluids with a small birchbroom. The linen, &c., is then put into this liquid and soaked for three

hours, care being taken to cover the washing-tub with a closely-fitting wooden lid; by this means the linen is readily cleansed, requires hardly any rubbing, and less brushing, and there is a saving also of time and fuel. Ammonia does not affect the linen nor woollen goods, and is largely used as washing-liquor in the North of England, of course along with much water, as above indicated.

GEOLOGY AND PALEONTOLOGY.

Fossil Turtles.-At the meeting of the American Philosophical Society, March 1, 1872, Professor Cope read a paper "On Protostega," a genus of extinct Testudinata. A detailed account of the osteology of P. gigas from the cretaceous beds was given, by which it appeared that the genus had separate ribs, as in Sphargis, and that the carapace was formed by large radiating plates of bone in the skin. Two other species were described-P. tuberosus and P. neptunus. The latter, the largest known marine turtle, from New Jersey; the former, from the cretaceous of Mississippi, had been referred by Leidy to the Mosasauroids.

Mr. Waterhouse Hawkins' efforts in New York have, we regret to learn, been completely overthrown by an ignorant manager of the Central Park Museum. In answer to an inquiry made of him, Mr. Hawkins says that all he had done during twenty-one months to restore the skeletons of the extinct animals of America (of the Hadrosaurus, and the other gigantic animal, which was thirty-nine feet long), was destroyed by order of Mr. Henry Hilton, on May 3, with sledge-hammer, and carted away to Mount St. Vincent, where the remains were buried several feet below the surface. The preparatory sketches of other animals, including a mammoth and a mammoth and a mastodon, and the moulds and sketch-models, were destroyed. Mr. Hilton did this, said Mr. Hawkins, out of ignorance, just as he had a coat of white paint put on the skeleton of a whale which Mr. Peter Cooper had presented to the Museum, and just as he had a bronze statue painted white. Mr. Hilton told the celebrated naturalist who had come from England to undertake the work that he should not bother himself with "dead animals;" that there was plenty to do among the living. This illustrates the policy of having such men as Hilton at the head of one of the most important departments of the City government. When the skeletons were dug up again, by order of Colonel Stebbins, they were found broken in thousands of pieces. Prof. Henry, of the Smithsonian Institution, when he heard of this piece of barbarism, would not believe it. "Why,” he exclaimed, "I would have paid them a good price for it." Mr. Hilton, however, preferred to destroy the work of the naturalist, which had cost the city at least 12,000 dollars.

Flint Arrow-heads.- We beg to recommend our readers to an excellent article on these weapons, which appears in the "American Naturalist" for April. It is certainly the ablest paper on this subject that we have seen, and it is abundantly illustrated.

New Species of Cretaceous Birds.-A very able paper on this subject appears in "Silliman's American Journal" for May, by Mr. O. C. Marsh. The few remains of birds hitherto described from the cretaceous deposits of

« AnteriorContinuar »