April Vi. 1895.] 



SCIENCE. 



415 



the outline of the Darwinian tlieory is an 

 exceptionally good one. Certain it is that 

 nothing in our literature at the present time 

 will give gueh a ter.se. clear presentation of 

 the Darwinian hypothesis \\'ith the argu- 

 ments in its favor, and of the additions 

 which have been made to this hypothesis 

 subsequent to the writings of Darwin 

 himself. 



These two books are, then, designed for 

 popular reading. Tliey are perhaps as good 

 an illustration of the especial character of 

 Prof. Marshall's power in teaching as could 

 be found. They are valuable additions to 

 that class of books in which the English 

 language is beginning to abound, viz., pop- 

 ular scientific writings that actually teach 

 gcknee. H. AV. Coxx. 



Wesleyan Uxivkrsity. 



Elements of Astronomy. — By Geokge "W. Par- 

 ker, of Trinity College, Dublin. Long- 

 mans, Green & Co., London and Xew 

 York. 8vo., 236 pages. 81.75. 

 The book is designed as a connecting link 

 between the elementary school-astronomies 

 and the higher treatises used as text-books 

 in the univei-sities. It treats the subject 

 almost exclusively from the geometrical 

 point of \-iew, breaking up the matter into 

 propositions, corollaries and problems, ar- 

 ranged in an order which is probablj' logical 

 enough in its mathematical sequence, but 

 strikes one as rather peculiar. The book 

 will be found useful by teachers who have 

 ' examination papers " to draw up, since it 

 presents a large number of them, as well as 

 numerous ' exercises ' and problems well 

 suited to test a student's understanding of 

 the subject-matter. 



"What the book professes to do is in the 

 main vi-ry well done. The statements and 

 definitions are intelligible and correct, and 

 the reasoning is generally clear and logical. 

 The writer's description of the instruments 

 and methods of practical astronomj- make 



it evident, liowevi-r, that he has had very 

 little actual experience in that sort of work. 

 It reads rather strangely, for instance, to 

 be told that the way to find the value of a 

 micrometer-screw revolution is to * note 

 how many turns correspond to the sun's 

 diameter.' 



Regarded as an elementary presentation 

 of 'Astronomy ' taken as a whole, the book 

 must be pronounced extremelj- one-sided 

 and defective. Astrophysics is most inade- 

 quately dealt with ; the whole subject or 

 spectroscopy is dismissed with six pages 

 and a single old diagram of the dispersion 

 of light b}' a prism ; and all phj-sical mat- 

 ters relating to sun, planets, comets, stars 

 and nebulse are treated on the same general 

 scale. C. A. Y. 



Qualitative Chemical Analysts of Inorganic 

 Substances — As practiced in Georgetown 

 College, D. C. American Book Co., New 

 York. 1894. 



Rev. H. T. B. Tarr, S. J., formerly pro- 

 fessor of chemistry in Georgetown College, 

 prepared a series of tables for analj-tical 

 purposes, which have been whollj^ recast 

 and incorporared into the work now before 

 us. The present editor. Rev. T. W. Fox, 

 S. J., speaks of the book as being ' useful in 

 a couree such as is given at Georgetown 

 and in similar institutions throughout the 

 country.' 



The ' gi-ouping of the bases ' is that gener- 

 ally adopted by writci-s on qualitative an- 

 alysis the world over. We believe, liow- 

 ever, that it would have been wiser and 

 better for the student had the author divided 

 his third group, consisting of the metals 

 precipitated liy ammonium sulphide from 

 neutral or alkaline solutions, into two 

 groups. But this is merely a matter of 

 opinion. 



"We obsen-e that the properties of the 

 metals are first studied, after which the 

 author draws up a table for the analysis of 



