i88o.J 
589 
Analyses of Books. 
The organogenic questions to be elucidated by embryology 
relate to the origin and homologues of the germinal layers, the 
origin of the primary tissues, and the origin and gradual evolu- 
tion of the organs and systems of organs. 
In expressing our general approval of Prof. Balfour’s work we 
do not wish to be misunderstood. It is by no means a popular 
treatise. It contains no novel or striking generalisations, and 
to readers unacquainted with morphological zoology it will prove 
scarcely intelligible. But to the student and the professed biolo- 
gist it may be recommended as affording a fair and comprehensive 
survey of the results hitherto reached in embryology, such as no 
other work in the language is calculated to afford. The illustra- 
tions are numerous and carefully executed, and the references to 
original memoirs accompanying the chapters and sections are 
ample. A second volume will treat of vertebrate animals, and 
with the special histories of the different organs. 
The chief defedt of the work is one which it shares with no 
small proportion of modern English biological works, — that is, 
the tendency to multiply technical terms of Greek origin. We 
see no good reason why we might not, like the Germans, employ 
technical terms of native origin. The days are passing away 
when every man of science may be assumed to be a classical 
scholar. 
Practical Chemistry. The Principles of Qualitative Analysis. 
By W. A. Tilden, D.Sc., F.C.S. London : Longmans 
and Co. 
The author tells us in his Preface that his book is intended for 
beginners, and that its produaion was prompted by the require- 
ments of his own teaching, and “ by the consideration that it is 
not necessary to learn the properties of any large number of 
substances in order to be in a position to understand the prin- 
ciples of chemical analysis.” All this is perfectly true : but 
among the elementary works on chemistry which have been pro- 
duced in such astonishing plenty during the last ten years, are 
there not several — to use the mildest expression in which the 
consideration of the rarer elementary bodies is omitted on pre- 
cisely the same grounds ? It cannot be expedted that a chemist 
of Dr. Tilden’s standing would be guilty of any error in com- 
piling a book of this simple charaaer, but we can scarcely see 
any locus standi for his work. Pending the avatar of some 
capital discovery which may essentially modify the outlines of 
the science, we think that there is no more need for the appear- 
ance of any further elementary treatises on chemistry. 
