336 Scientific Intelligence. 



gen sulphide is produced; but at 165° abundance of the latter 

 gas is evolved, and torrents of it at 180°, with but little of the 

 sulphur dioxide. Approximately pure zinc interacting with the 

 same acid at 160° gives both gases in abundance. With regard 

 to the appearance of sulphur, the authors are disposed to regard 

 it neither as a product of the interaction of SO„ and H 2 S, nor as 

 produced by the reducing action of the hydrogen upon the S0 2 ; 

 but as rather due to the mutual action of hydrogen sulphide and 

 hot concentrated sulphuric acid. In general it appears that the 

 interaction between approximately pure zinc and acid is chiefly a 

 direct chemical interaction and that the products of the reactions 

 with the less pure zincs are largely due to the occurrence of 

 secondary electrolytic changes. — J. Chem. Soc, liii, 47-58, Jan., 

 1888. G. F. b. 



4. Organic Analysis ; A Manual of the Descriptive and 

 Analytical Chemistry of certain Carbon Compounds in common 

 use. By Albert B. Prescott, Ph.D., M.D., Director of the 

 Chemical Laboratory of the University of Michigan, etc. 8vo, 

 pp. 533. New York, 1887 (D. Van Nostrand.)— This book ap- 

 pears to be a valuable addition to the literature of technical 

 analysis. For the compounds of which it treats, it furnishes, 

 first a systematic chemical description of these compounds, fol- 

 lowed by the qualitative and quantitative methods to be pursued 

 in their examination, together with tests for their purity. The 

 titles are arranged alphabetically for convenience of reference. 

 The references given are copious and reliable. Among the articles 

 which seem to us especially valuable are those on the alkaloids, 

 classified as the aconite, the cinchona, the cadaveric, the midriatic, 

 the opium and the strychnos alkaloids; those on elementary 

 analysis, on fats and oils, on coloring matters and on the tannins. 

 Considerable care has evidently been exercised not only in select- 

 ing the titles so as to include substances likely to be offered for 

 examination, but also in giving the results of the latest investi- 

 gations. For clearness, completeness and accuracy, the book will 

 add to the already excellent reputation of its author. It is 

 provided with a full index and is printed and bound in a very 

 satisfactory manner. G. f. b. 



5. Practical Physics for Schools and the Junior Students of 

 Colleges; by Balfour Stewart and W. W. Haldane Gee. 

 Vol. I. Electricity and Magnetism. 16mo, pp. xviii, 221, London, 

 1888 (Macmillan & Co.) — This little book, though elementary, 

 is one of the best of its kind in the language. The arrangement 

 is excellent, the experiments well chosen, the descriptions and 

 discussions clear, and the exercises admirably adapted to fix the 

 text in the mind of the student. Morever the apparatus required 

 is simple, much of it being constructed by the pupil himself. 

 We commend the book to. those teachers who are engaged in 

 elementary physical laboratory instruction, as admirably suited 

 to their needs. G. f. b. 



