138 



SCIENCE. 



[Vol. XX. No. 500 



order that the most essential features shall be presented. He is 

 evidently a master of the whole science, and not an amateur con- 

 tent to explain the familiar portions and to overlook the difiScult 

 topics needful to make the sketch symmetrical. Wisdom is also 

 shown in the classification and description of the minerals. The 

 thoroughly scientific arrangement by chemical character, of use 

 lo the learned, is laid aside for the following practical scheme: 

 First, the rock-forming minerals, such as are world-wide, and ex- 

 tend through the whole crust; second, the ores; third, the salts 

 and useful minerals suppleraentai-y to the ores; and fourth, the 

 gems and precious stones. Under the first head there is presented 

 the important distinction of those that have been formed second- 

 arily in contrast with those that were original. We think the 

 author might wisely have devoted three or four pages, instead of a 

 brief paragraph scarcely exceeding fifty words, to the hydro-car- 

 bons. No effort is made to describe the phenomena connected 

 with refraction and polarization, nor to the microscopic structure, 

 nor to petrography. 



Notes and Examples in Mechanics. By lEvmo P. Chdrch. New 

 York, John Wiley & Sons, 1892. 



This work, as stated in the preface, is "a companion volume 

 to the writer's 'Mechanics of Engineering,' and contains various 

 notes and many practical examples, both algebraic and numerical, 

 serving to illustrate more fully the application of fundamental 

 principles in mechanics of solids; together with a few paragraphs 

 relating to the mechanics of materials, and an appendix on the 

 "Graphical Statics of Mechanism." A knowledge of the elements 

 of trigonometry and calculus is assumed. 



The work is clear and practical. Many problems are first 

 treated analytically, then by assuming numerical values for the 

 several algebraic quantities. English units are used. Engineer- 

 in"' data are drawn from well-known and reliable authorities. 



Among the structures and machines discussed (after the neces- 

 sary exposition of general principles) are the bell crank, simple 



and compound cranes, wedge, roof truss, pendulum, weighted 

 piston with steam, I-beam, box-beam, fly-wheel, locomotive, jack- 

 screw, ore-crusher, etc. 



The work is abundantly illustrated with cuts. 



Light. By Sir H. Trueman Wood. London, Whittaker & Co., 

 1891. 



This elementary Treatise belongs to Whittaker's " Library of 

 Popular Science.'' The undulatory theory is presented in clear 

 and non- mathematical language, and the various phenomena of 

 common observation are explained on this theory. 



In a very lucid and attractive style, the author discusses such 

 topics as reflection, refraction, color, optical instruments, the 

 chemical action of light (as in photography), polarization, and 

 fluorescence. The cuts are abundant and well drawn. 



The appendix contains an annotated list of elementary works 

 on light, color, spectroscope, etc. 



Chemical Calculations, with Explanatory Notes, Problems, and 

 Answers. By R. Lloyd Whitet.ey. London and New York, 

 Longmans, Green & Co. 1893. 



A WIDE range of topics is included in these hundred pages; as 

 metric system, thermometric scales, density and specific gravity, 

 percentage composition of compounds, calculation of empirical 

 formula, volume of gases, calculations depending on chemical 

 equations, combination of gases by volume, calculation of the re- 

 sults of quantitative analysis, atomic weight determinations, gas 

 analysis, absorption of gases by liquids, molecular weights, cal- 

 orific power and calorific intensity. 



The problems on molecular weights are not confined to vapor 

 densities; but the more recent methods of freezing points (Raoult) 

 and boiling points (Beckmann and Wiley) are duly explained. 



The table of atomic weights is based upon O = 16, and agrees, 

 for the most part, with Ostwald s "Outlines of General Chem- 

 istry;'" thus H — 1.003. in accordance with the older determina- 



Publications Received at Editor's Office. 



DAT, David T. Mineral Resources of the United 

 States. Waslilngton, Government. 8°. 678 p. 



Garnkk, H. L. Toe Speech of Monkeys. New York, 

 Charles L. Webster & Co. 8°. 233 p. 



JACKMAN, Wilbur S. Nature Study for the Common 

 Schools. New York, Henry Holt & Co. 12°. 

 448 p. 



Merrill, George P. The Materials of the Earth's 

 Crust. Washington, Government. 8°. Paper. 

 87 p. 



SALTER, William M. First Steps in Philosophy. 

 Chicago, Charles H. Kerr & Co. 12°. 155 p. $1. 



TJ. S. Department of agriculture. Insect Life. 

 Washington, Government. 8°. Paper. 90 p. 



" Watekdale." Researches on the Dynamic Action 

 and Ponderosity of Matter. London, Chapman 

 & Hall. 12°. 309 p. 



Watkins, J. E. The Log of the Savannah. Wash- 

 ington, Government. 8°. Paper. .30 p. 



Wells, Charles R. Manual of the Natural Move- 

 ment Method in Writing. Syracuse, C. W. Bar- 

 deen. Sm. 4°. Paper. 44 p. 25 cts. 



Williams, Samuel G. The History of Modern Edu- 

 cation. Syracuse, C. W. Bardeen. 12°. 403 p. 

 $1.50. 



Beading Matter Notices. 



Kipans Tabules : best liver tonic. 

 Kipans Tabules cure jamidice. 



FOR SALE. 



The Paleontological Collection of the late 

 U. P. James, of Cincinnati, Ohio. Many 

 type specimens and thousands of duplicates. 

 For further information address 



JOSEPH F. JAMES, 



U. S. Department of Agriculture, 



Washington, D. C. 



Societas Entomologica. 



International Entomological Society, Zu- 



rich-Hottingen, Switzerland. 



Annual fee, ten francs. 



The Journal of the Society appears twice a 

 month, and consists entirely of original ar- 

 ticles on entomology, with a department for 

 advertisements. All members may use this 

 department free of cost for advertisements 

 relating to entomology. 



The Society consists of about 4.50 members 

 in all countries of the world. 



The new volume began April 1, 1892. The 

 numbers already issued will be sent to new 

 members. 



For information address Mr. Fritz Euhl, 

 President of the Societas Entomologica, 

 Zurieh-Hottingen, Switzerland. 



INDEXES 



Volumes XVII. and XVIII 



SCIENCE 



are in preparation, and will be 

 issued at an early date. 



POPULAR MANUAL OF VISIBLE SPEECH AND 

 VOCAL PHYSIOLOGY. 



For use in Colleges and Normal Schools. Price 50 cents 

 Sent free by post by 



N. ». C. HODGES, 8 74 Broadway, N. Y. 



Wants. 



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