EXTRACTION OF OXYGEN FROM THE AIR. MM. Laire and Montmagnon propose to take advantage of the well-known property of wood charcoal, alkaline solutions, and blood, of absorbing a larger portion of oxygen from the surrounding air than of nitrogen. It is proved, by experiment, that 100 measures of wood charcoal, freshly burned, absorb 985 of oxygen, and only about 705 of nitrogen. The blood of animals and solutions of phosphate and carbonate of sodium absorb rapidly, according to the amount of surface exposed to the air, about 12 per cent. of oxygen, and only two per cent. of nitrogen. The proposed method of utilizing these facts in this: -Pump out the oxygen and nitrogen from the substances used to absorb it by means of an air-pump; pass the mixture through fresh absorbing media; re-extract, and repeat the operations as often as required. In this way an oxygen is obtained very free from nitrogen, and at an extremely cheap rate. ·British Journal of Photography. ENAMELS. The fine enamels of trade are generally prepared by fusing, at high temperatures, silica, oxide of tin, and oxide of lead, and spreading the mixture over the surface of a sheet of copper, of gold, or of platinum. The objections to these enamels are, in the first place, their high cost, and, secondly, the impossibility of giving them a perfectly flat surface. Mr. E. Duchemin has advantageously replaced them by the following economical and efficient compound: Arsenic, 30 parts by weight; saltpetre, 30; silica (fine sand), 90; litharge, 250. This is spread on plates of glass of the required shape and size, care being taken, however, that the kind of glass employed be not inferior in point of fusibility to the enamel. Enamelled glass prepared from the above substances may be drawn or written on as readily as if it were paper, and in less time than one minute the writing may be rendered indelible by simply heating the plate in a small open furnace or muffle. First-class photographs, either negatives or positives, may be taken on such enamels without collodion, by using bitumen, or citrate of iron, or perchloride of iron and tartaric acid, or bichromate, or any other salt. A good solution for this purpose is, water, 100 parts by weight; gum, 4 parts; honey, one part; pulverized bichromate of potassium, 3 parts. Filter the liquid, spread it over the enamel, and let it rest, after which: 1. Expose it to the camera. 2. Develop the image by brushing over it the following powder: Oxide of cobalt, 10 parts by weight; black oxide of iron, 90 parts; red lead, 100 parts; sand, 30 parts. 3. Decompose the bichromate by immersion in a bath formed of, water, 100 parts by weight; hydrochloric acid, 5 parts. 4. Wash it in clean water and dry it. 5. Vitrify the proof on a clean piece of cast iron, the surface of which has been previously chalked. One minute will suffice for indelibly fixing and glazing the photograph, which must be carefully and slowly allowed to cool. Photographs on enamel of any size, taken in this manner, are perfectly unalterable under all atmospheric conditions, and may consequently and aptly be called "everlasting photographs."Scientific American. PRESERVATION OF WINES. The process for improving and preserving wines, originally proposed by Pasteur in his "Etudes sur le Vin," by simply heating it to a temperature of 55° to 75° C. (131° to 167° F.), previous to bottling, or after partial decomposition had set in, has lately been reported upon by a commission of the French Navy Department a series of experiments and trials on an extensive scale having been made for the purpose of determining its value. The report states that Pasteur's process will preserve French wines permanently, or for an indefinite length of time, from acidity and change of taste or clearness; that a temperature of from 55° to 60° C. (131° to 140° F.) is the one desirable to apply to the wines; and that this heating should be performed in vessels of tin or tinned copper. · Dingler's Journal, from Armengaud's Génie. ANALYSIS OF LAGER BEER. Prof. C. F. Chandler, of the School of Mines of Columbia College, has recently concluded a series of chemical tests with lager beer, undertaken in order to ascertain the extent of its intoxicating properties, and the hygienic character which it has been represented to possess. His report is eminently successful in proving that the nourishing qualities which have been ignorantly assigned to lager beer are only fictitious, and also that it is entirely objectionable as a drink. It is composed chiefly of water, with a certain amount of alcohol, enough to cause intoxication when copiously imbibed. During the brewing of the beerwhich, if properly done, occupies 8 months, the brewing commencing in cold weather-great care has to be taken to prevent its becoming mouldy, which it sometimes does by the slightest variation in temperature. It is necessary to cool the brewing-vault in summer and warm it in winter, in order to keep it at the requisite temperature, averaging from 41 to 45 degrees Fahrenheit. Frequently, however, the weather continues to act on the beer after it has been barrelled and sold to retail dealers, rendering it flat and bitter, in which condition it is very often sold as a drink. Prof. Chandler's analyses embraced 5 samples of different breweries, which, when examined, developed trifling and unimportant differences in their quality. The following is the tabulated result: It was found that all the specimens contained small quantities of grape sugar; of lupuline, the bitter principle of the hops; of acetic acid (merely a trace), produced by oxidization of some of the alcohol; and of carbonic-acid gas generated during the fermentation. A most thorough examination failed to reveal any indications of the presence of picric acid, picrotoxin (the peculiar principle of cocculus Indicus), alum, copperas, or any other adulteration whatever. — Druggists' Circular NEW ALKALOID IN FERMENTED LIQUORS. According to M. Ozer, every time that solutions of sugar ferment under the influence of yeast, beside alcohol, a new alkaloid is produced, to which he attributes the formula C H20 N4. The chlorhydrate of this base crystallizes in hygroscopic tables, which become brown on exposure to the air. It appears that all fermented liquors contain the new alkaloid, or at least one of its compounds. The existence of this new alkaloid may explain certain effects of fermented liquors which cannot be attributed to alcohol alone. - Cosmos. TURACINE. The turaco, or plantain-eater, of the Cape of Good Hope is celebrated for its beautiful plumage. A portion of the wings is of a fine red color. This red coloring matter has been investigated by Prof. Church, who finds it to contain nearly 6 per cent. of copper, which cannot be distinguished by the ordinary tests, nor_removed from the coloring matter without destroying it. The coloring matter is, in fact, a natural organic compound, of which copper is one of the essential constituents. Traces of this metal had previously been found in animals; for example, in oysters, to the cost of those who partook of them; but in these cases the presence of the copper was merely accidental; thus, oysters that lived near the mouths of streams which came down from copper mines assimilated a portion of the copper salt without apparently its doing them either good or harm. But, in the turaco, the existence of the red coloring matter which belongs to their normal plumage is dependent upon copper, which, obtained in minute quantities with the food, is stored up in this strange manner in the system of the bird. Thus, in the very same feather, partly red and partly black, copper was found in abundance in the red parts, but none, or only the merest trace, in the black. This red coloring matter is soluble in water; and a pair of birds, kept in captivity, lost their fine red color in the course of a few days, in consequence of washing in the water which was left them to drink; except as to the loss of their beauty, however, it does not appear that the birds were the worse for it. Address of President Stokes before the British Association, 1869. ALIZARINE. M. Martin, taking advantage of Shützenberger's investigation of madder, has invented a process for transforming orangemadder, purpurine, pseudo-purpurine, and tantho-purpurine, into alizarine. The several coloring matters are first dissolved in concentrated sulphuric acid; powdered zinc is then added, and heat applied. When the reaction is completed, the mass is diluted with water, and an abundant precipitate falls, which is the required dye. This, after washing with water, is ready for use. Chem. News. ARTIFICIAL ALIZARINE. Messrs. Græbe and Liebermann, of Berlin, have discovered a process for converting anthracene (paranaphthaline), a constituent of gas-tar, into alizarine, the principal coloring matter of the madder-plant. This conversion is accomplished by three successive operations: First: the anthracene (C14 Hg) is transformed into oxanthracene, or anthraquinone (C14 H10) by heating one part of anthracene with two parts of bichromate of potassium in the presence of sulphuric acid or of crystallized acetic acid, or by the action of a mixture of nitric and acetic acids. Second: the anthraquinone is heated with two equivalents of bromine, and the product formed heated with alcoholic potash. There results the compound C14 H6 Br4, and from this, by the oxidizing action of nitric acid and bichromate of potassium, is obtained the brominated compound C14 H6 Br2 O2, which is purified by recrystallization. In this process chlorine can be used instead of bromine. Third: the brominated compound thus formed is heated with a very concentrated solution of potash to from 180° to 260° C., until the blue color which the mass assumes no longer increases in intensity. The mass is then treated with an acid which precipitates the alizarine. -Bull. Soc. Ch., June, 1869. MM. Græbe and Liebermann have recently stated that they can dispense with the use of acetic acid and bromine, and will shortly be able to bring into the trade a superior article manufactured by a method different from that already described by them. Mo. Sci. NEW DYE FROM MADDER. Prof. Rochleder, of Prague, has found that, when madder is treated with dilute mineral acids, it yields, beside alizarine and purpurine, a small quantity of a third tinctorial substance, which in alkaline solution has a great similarity to chrysophanic acid in alkaline solution; acids precipitate it from this solution in the amorphous, flocculent state, the precipitate being of a pale yellow color. This substance is soluble in alcohol and acetic acid, from which solutions it is obtained by evaporation in orange-yellow colored crystals. Its aqueous solution, mixed with acetic acid and brought to the boiling point, imparts to silk and wool a beautiful and durable golden-yellow color. — Cosmos. A NEW COLORING MATTER. The discovery of fuchsine and other colors derived from aniline first caused the existence of very rich sources of coloring matters to be predicted in mineral oils and hydrocarbons in general. Therefore, since that period, chemists have devoted themselves to laborious researches in the same direction, in order to find new products for use in dyeing. The method which M. Clavel has adopted was suggested by the study of the circumstances, which have since been explained, regarding the formation of fuchsine. It is now known that commercial aniline is a mixture of aniline and toluidine; and M. Hofmann has proved that it is a mixture of these two bases which produces the brilliant color. Guided by an examination of these facts, M. Clavel has not sought in naphthylamine for a coloring matter by itself, but for one likely to produce the color, by a mixture with another base like naphthylamine, from which it has been derived, or with any other isomeric substance. The new coloring matter, then, is obtained by the direct oxidation of a product isomeric with naphthylamine and mixing the products of higher distillation with the naphthylamine. The mode of operation is as follows: The naphthaline is first treated with nitric acid of 1.33°, and the resulting nitronaphthaline is washed, and reduced either by iron and acetic acid, or by zinc and hydrochloric acid, or by other appropriate reagents. The distillation is then proceeded with. There comes over at first naphthylamine, and then at a higher temperature a second body discovered by M. Clavel. This second product is treated at 120° with 50 per cent. of very dry nitrate of mercury, and subsequently left in contact with its own bulk of naphthylamine for about a quarter of an hour; the mixture is then treated with boiling water containing a vegetable acid, by which the coloring matter is dissolved. After filtration |