which is so dangerous to the ordinary process. First, sulphoglyceric acid is made by treating glycerin of 30° by three times its weight of sulphuric acid of 66°. Second, nitrosulphuric acid is made by mixing equal weights of nitric acid at 48° and sulphuric acid at 66°. After cooling these liquids separately, they are mixed so as to get 100 parts of glycerin, 280 of nitric acid, and 600 of sulphuric acid. The temperature never rises more than 10° to 15°, and the nitroglycerin may be directly decanted and washed. The yield is from 160 to 195 per cent.

A paper has appeared by Bischof, giving the results of his examination of a considerable white efflorescence upon the outside of a tube which had been employed for eight months in conveying aqueduct water into a cistern, the tube being alternately exposed and immersed. The powder was lead carbonate and sulphate. On analyzing the tube itself, it was found to contain 1.7 per cent. of antimony. The author attributes the rapid corrosion to the presence of this metal, and considers the use of lead alloys for tubes for conveying drinking-water to be reprehensible.

Heeren has examined various kinds of caoutchouc to ascertain their solvency in coal-tar benzene. He finds the most soluble to be that of Guayaquil, of which benzene dissolves 20 per cent.; while that of Para has only 17 per cent. of soluble matter; Africa, 12.7; Rangoon, 9.1; and Madagascar, 5.7. Obviously this gum must be, therefore, a mixture of several different chemical substances.

Berthelot has given a description and an analysis of an ancient wine, fifteen or sixteen centuries old, obtained from an hermetically sealed earthenware vase in the Borely Museum at Marseilles. It came originally from Aliscamps, near Arles, in a vicinity used as a cemetery during the Roman epoch. It contained about twenty-five cubic centimeters of a yellowish liquid of a vinous aromatic odor and a hot, strong taste. On analysis it yielded, per liter, 45 centimeters of alcohol, 3.6 grams fixed acids (calculated as tartaric), 0.6 hydropotassium tartrate, 1.2 acetic acid, calcium tartrate and acetic ether, traces. The wine appears to have been buried

with the dead.

Baudrimont has given a simple method for recognizing the presence of fuchsin (aniline-red) in wine. A drop is placed

on the hand and allowed to remain there a few seconds. On removing the wine, a mark is left which cannot be washed out with water.

Jacquemin has examined the methods proposed for the detection of fuchsin in wine, founded on its tinctorial power. As is well known, this substance is extensively used for this purpose. Pyroxylin and wool may be dyed directly in the wine, but to prove the presence of fuchsin finally, the ammonia process is necessary.

Maumené has published an extended memoir on an improved method of alcoholometry for determining the strength of wines, by distilling them first after making them alkaline, and then the distillate after making it acid. The memoir discusses at length the effects of the various foreign matters. present in wine upon the result, and concludes that the improved method leaves nothing to be desired.

Erismann has investigated very thoroughly the question. of the contamination of the air arising from artificial illumination and the distribution of the carbon dioxide in close rooms. He finds that the injurious effect cannot always be calculated from the absolute amount of carbon dioxide present, since the quantity of the illuminating substance which always escapes unburned is variable with the temperature and the illuminant used. Moreover, the contamination bears no necessary relation to the amount of light obtained. The conclusions reached are: 1st, in every case of artificial illumination the air of a close room contains more carbon dioxide and organic matter than when no light is present; 2d, the proportion of marsh gas to carbon dioxide varies, not only with the nature of the burning material, but also in different strata of the air of the room when the same material is employed, the ratio being never constant; 3d, air should never contain more than 0.6 or, at most, 0.7 per thousand of carbon dioxide, otherwise products of imperfect combustion are present in large quantity; though, on the other hand, a small quantity of this gas is no evidence of freedom from these; 4th, the position of the air-stratum in which most products of combustion are found depends on the nature of the burning material, the higher strata being most impure when candles are employed, though the larger part of the carbon dioxide from combustion is removed by

ventilation; and, 5th, petroleum, when burned in well-constructed lamps, gives rise to less carbon dioxide, and, what is more important, to less imperfectly burned matter, than any other illuminating agent. For equal light, stearin candles render the air most impure, the proportion for petroleum, gas, oil, and candles being 1:4:4:7. An ordinary room of a capacity of 100 cubic meters would contain, if lighted with petroleum (the light being equal to six candles), 56 cubic centimeters of carbon dioxide and 1.7 of marsh gas; if lighted with gas, 47 and 6.9 cubic centimeters; with oil, 109 and 7.2 cubic centimeters; and with candles, 125 and 18.7 cubic centimeters; the cost of the petroleum for 24 hours being 5 cents, of the gas 13 cents, of the oil (rape oil) 15 cents, and of the candles 72 cents.

Coquillion has proposed a new method for detecting and estimating the amount of fire-damp in mines. As is well known, the blue aureole which surrounds the flame of the safety-lamp when in an explosive atmosphere is the only means at present in use for ascertaining the presence of fire-damp, but this requires at least 6 to 8 per cent. of marsh gas to produce the effect. The new method is founded on the fact, first observed by him, that hydrogen and hydrocarbons generally are completely burned in presence of oxygen, and without detonation, by means of a palladium wire brought to a white heat. The carbon dioxide thus generated is afterwards estimated in a graduated tube. Two pieces of apparatus have been made-one for use in the mine, which detects the carbon dioxide produced by the incandescent palladium, and thus shows the fire-damp; the other for use above ground, in determining accurately the amount present.

Bischof has examined the action of spongy iron upon the low forms of organic life which form the specific poison of cholera, typhoid fever, etc. He finds that bacteria are rendered permanently harmless when passing into water through spongy iron. Even effluent sewage water, after passing through the spongy iron, remained perfectly clear for five years, though exposed to both light and air. The author asserts that the action of this material consists largely in the reduction of the ferric hydrate, the ferrous compound resulting being again oxidized by the oxygen in the water.

Prominent

MINERALOGY.

By EDWARD S. DANA, Ph.D.,

YALE COLLEGE, New Haven, CONNECTICUT.

RECENT PUBLICATIONS.

among the contributions of the past year to the literature of mineralogy stands the tenth edition of Naumann's standard work. It is not too much to say that, since the publication of the first edition in 1846, it has always occupied the foremost place among German Mineralogies. The author closed his long and active career in November, 1873, just as the ninth edition of his work had been given to the public. The present edition has been prepared by Professor Zirkel, of Leipsic, well known for his many contributions to the subject of microscopical lithology. He has retained the general arrangement of the book, but has changed the method of classification, adopting the much-to-be-preferred chemical system in the place of that employed by Naumann. This, it need hardly be added, increases much the value of the work.

A second volume of Rosenbusch's "Mikroskopische Physiographie der Mineralien und Gesteine" has recently appeared. The first volume, devoted to the description of the microscopical characters of the important minerals, was published in 1873. The second part of the work is somewhat more extensive than the former, running to about six hundred pages, and is devoted to lithology. Both volumes derive much of their value from the fact that they embody the results of the author's own extended researches. Professor Zepharovich, of Prague, has edited a series of large crystallographical figures designed for class instruction. They include the most important crystalline forms under the different systems, and are drawn on so large a scale as to be adapted for wall-charts, in which form they will doubtless be found very useful.

The publication of a new edition of Kenngott's Mineralo

gy, and the appearance of a mineralogical treatise by Pisani in Paris, are also deserving of mention.

In this country there has appeared a second "Report of the Mineralogy of Pennsylvania," by Dr. F. A. Genth; also Dana's "Text-book of Mineralogy," a work of about five hundred pages; and a new edition of Weisbach's Tables edited by Professor Frazer.

The new journal (Zeitschrift für Krystallographie) published by Professor Groth in Strasburg has now completed its first year, and has more than fulfilled the promises of the prospectus alluded to in the last volume of the Record. The first volume, in six numbers, covers about six hundred and fifty pages, with a large number of plates. It contains many valuable papers, as would be expected; but, perhaps more important than these, it includes also abstracts of most of the mineralogical memoirs published during the year, not only in other German periodicals, but also in English, American, French, Italian, Spanish, and Swedish journals. It thus furnishes a quite complete record of the progress of the science during the year.

The Mineralogical Society of Great Britain and Ireland has now issued six numbers, containing the records of its meetings, and also a number of original contributions.

FOREIGN RESEARCHES.

Of the many foreign mineralogical memoirs, mention can be made only of a very few; reference must rather be made for them to the journals that have been spoken of, as well as to the many other older and well-known publications. A list of the new species which have been described is given on a following page.

Mr. H. C. Sorby has added to his many important memoirs a most valuable research-"On the Determination of the Chief Optical Constants of Minerals by Means of a New Class of Optical Properties." It is published in No. 6 of the Mineralogical Magazine. The method consists in the determination, in thin sections of minerals, of their mean refractive index by simple observations with the microscope. Briefly described, this is done by measuring the amount of displacement which the focus of a certain object, as a set of finely ruled parallel lines on glass, suffers when a highly refractive