Page:Popular Science Monthly Volume 16.djvu/740

 Flückiger and Daniel Hanbury, F.R.S. London: Macmillan & Co. 1879. Pp. 803. $5.

A Handbook of Double Stars. By Edward Crossley, Joseph Gledhill, and James M. Wilson. London: Macmillan & Co. 1879. Pp. 464. $6.

The Microscope in Medicine. By Lionel S. Beale. Philadelphia: Lindsay & Blakiston. 1878. Pp. 528. $7.50.

A Treatise on Vocal Physiology and Hygiene. By Gordon Holmes, F.R.C.P. Philadelphia: Presley W. Blakiston. 1880. Pp. 268. $2.

The Refutation of Darwinism and the Converse Theory of Development. By T. Warren O'Neill. Philadelphia: Lippincott & Co. 1880. Pp. 544. $2.50.

Sunshine and Storm in the East. By Mrs. Brassey. With upward of a Hundred Illustrations. New York: Henry Holt & Co. 1880. Pp. 448. $3.50.

England: her People, Polity, and Pursuits. By T. H. Escott. New York: Henry Holt & Co. 1880. Pp. 625. $4.

The Metaphysics of the School. By Thomas Harper. London: Macmillan & Co. 1879. Vol. I., Pp. 592. $5.

A Manual of the Antiquity of Man. By J. D. Maclean. Cincinnati: Robert Clark & Co. 1879. Pp. 159. $1.

How to educate the Feelings or Affections. By Charles Bray. Edited by Nelson Sizer. New York: S. R. Wells & Co. 1880. $1.50.

 

Action of Organic Acids on Minerals.—At a recent meeting of the New York Academy of Sciences, Professor H. Carrington Bolton, of Trinity College, Hartford, communicated the results of a continuation of his researches on the behavior of minerals with organic acids. In a previous paper (read in 1877) he gave the reactions of ninety-five minerals with citric acid; in the present paper he extended the investigation to two hundred species. Dr. Bolton stated that citric acid has a power of decomposing all classes of minerals little less than that possessed by hydrochloric acid, and that this very difference in degree gives the organic acid an advantage over the mineral acid in the determination of species. Besides treating the minerals with a saturated solution of citric acid, he examined the action of the same solution, to which solid sodium nitrate is added. This mixture proves to be a very powerful solvent, dissolving bismuth, antimony, arsenic, copper, lead, tin, mercury, and silver, and nearly all the natural sulphides. The addition of solid potassium iodide to the solution of citric acid also greatly increases its decomposing power. Applying these reagents to minerals, Dr. Bolton obtained the following results: 1. Complete solution of carbonates, with liberation of carbonic-acid gas. 2. More or less complete decomposition of oxides, phosphates, etc. 3. More or less complete decomposition of sulphides, with liberation of sulphuretted hydrogen. 4. Decomposition of sulphides, with oxidation of the sulphur. 5. Decomposition of silicates, with separation of slimy or gelatinous silica. 6. Decomposition of certain species, with formation of characteristic precipitates. 7. Wholly negative action. The exact behavior of each of the two hundred minerals was given in a printed table, copies of which the speaker distributed to the audience. The application of this investigation is twofold: 1. The utility of the methods in field-work, owing to the portability of the reagents in a dry state; and, 2. The relation of these reactions to the geological work of the organic acids of the soil. The latter point is of much importance, and merits further researches.

How Snakes shed their Skins.—Under the title "About Snakes" in this department of our last number, we gave Dr. H. F. Hutchinson's mode of accounting for the way snakes get out of their old skins. Professor Samuel Lockwood, of Freehold, New Jersey, has witnessed the process, and, from a description of it given in his own inimitable style in a late number of "Nature," we gather the following interesting facts, which, as will be seen, do not support the hypothesis of Dr. Hutchinson: A female snake had already begun to cast her skin when Professor Lockwood made ids first observation, but the process was going on very slowly. The skin was slightly torn at the snout, and the head and a little of the neck were denuded. As it separated from the neck it had a sort of "back-creeping aspect"; there was no rubbing against exterior objects, and indeed it looked as if the change going on might be the work of an invisible power. Closer observation showed that there was a systematic alternate swelling of the body at the neck of the skin, thus stretching it, and making a shoulder in front of this neck, each swelling pushing the loosened skin a little backward. As soon as the process reached the larger ribs it went on more rapidly, and in the following way: