EE VIEWS. 
301 
his opinion, it must be at once said that, somehow or other, the result 
of reading it is unsatisfactory. If truth must he told, the volume is- 
one which neither possesses the information that is required by the earnest 
student, nor places the facts of the science in so popular a position that 
the unlearned in chemistry may read it with profit. We might take 
several examples of this tendency of the hook, hut one or two will suf- 
fice. We turned in the first instance to the chapter on Polarisation, 
as in that we were sure to find the author’s popular mode of teaching 
put to a severe test. But what did we find ? Why, that he has just 
given the usual explanation, and has not attempted anything in the way 
of genuine popularisation. W e confess that if we were unacquainted with 
physics, and turned to Dr. Youmans’ work for an explanation of this complex 
phenomenon, we should he no wiser after reading his account than we were 
before. But we will take another example in order to show our readers- 
that we are entirely unprejudiced in the matter, and that Dr. Youmans is 
absolutely incapable of really popularising a difficult subject. The quotation 
we will make refers to the theory of Atomicity and Quantivalence ) and Dr. 
Youmans’ remarks on the subject of “ variable combining capacity ” are as- 
[ ! follows : — “ The general theory of chemistry now adopted is the outgrowth 
! of preceding theories, and embodies the truths they have severally attained. 
But it adds an important principle which throws further light upon chemical 
operations, and serves to organise into a better system the later facts and 
ideas of the science. The notion of equality between combining elements 
and of equivalence among their atoms has long been fundamental in chem- 
istry. When the substitution theory arose,” &c., &c. 
We think we have given enough to create dismay in the minds of all 
lovers of genuine popular science. However, there is something to be said 
in the author’s favour. He has popularised many important points with 
considerable success, and he has supplied diagrams and drawings very 
freely, while withal he has furnished a series of questions at the termina- 
tion of the book which will, we doubt not, be found extremely useful by the 
young student. 
HE Professor of Zoology in the University of Dublin has long been known 
as a comparative anatomist of no mean ability, more' especially in 
regard to those classes of the animal kingdom which come beneath the divi- 
sion Yertebrata. But we have not heard of him as one who was specially 
devoted to the various Invertebrate groups of animals. Yet it is especially 
on the classes that are included in the Protozoa, Ccelenterata, Molluscs,. 
Annulosa, &c., that we find him writing in the present volume. We note, 
moreover, that he is modest enough in his preface, for he assumes that his 
book will form, as it were, a sort of introduction to the works of Rolleston, 
Huxley, and Flower. However, we fancy that most students will find that 
* “An Introduction to Animal Morphology and Systematic Zoology.” Bv 
A. Macalister, M.B., Professor of Comparative Anatomy in the University of 
Dublin. Part I. Invertebrata. London : Longmans. 1876. 
ANIMAL MORPHOLOGY. * 
