582 
NATURE 
[Aprit 18, 1907 
The volume on ‘ Qualitative Analysis,» by Dr. 
Morgan, is less a work for the beginner than for 
the student who has already acquired a_ certain 
familiarity with experimental chemistry. It is, in 
fact, a comprehensive study of analysis from the 
theoretical side. The author has not merely raised 
his cap to the new teaching and adopted the old, lilke 
some authors referred to in this notice, but has boldly 
plunged into the ionic hypothesis and consistently 
adhered to it. The book is divided into sections, the 
first of which deals with general principles, such as 
mass equilibrium, reversible changes, and 
dissociation; the second section is devoted to re- 
actions of the common elements, arranged according 
to the periodic system, and the third deals with 
systematic analysis. It is simply and clearly written, 
although the American spelling and the alternate use 
of names and symbols in the text are a little confusing 
to the English reader. Nevertheless, the book has a 
distinct character of its own; it is interesting and 
suggestive, and will fill a gap in chemical philo- 
sophic literature. 
Newth’s ‘Smaller Chemical Analysis”? is an 
abridged edition of the qualitative section of the 
““manual,”’ and includes a few quantitative exercises. 
The small edition possesses the characteristic features 
of the deservedly popular parent volume. For the 
student who is not intending to become a chemist, 
but who is taking chemistry as an adjunct to other 
studies, this abridgment will give him a very good 
notion of analysis. He will learn a little manipula- 
tion, the use of reagents, and the behaviour of the 
common metals and acids. There is nothing that is 
really novel in the treatment of the subject. A pass- 
ing reference is made to ionic dissociation, but the 
theory is not actually applied. The figures which 
are talken from the ‘‘ manual’ are excellent, with 
perhaps the exception of the drawing of the wash- 
bottle and blow-pipe, in which the operator’s 
moustache seems to form an essential part of the 
apparatus. Io 135 (Gs 
action, 
OUR BOOK SHELF. 
Animal Micrology. Practical Exercises in Micro- 
scopical Methods. By Dr. Michael F. Guyer. Pp. 
Ix+240. (Chicago: University of Chicago Press; 
London: T, Fisher Unwin, 1906.) Price gs. net. 
Tue term “‘ micrology ’’ has not received any general 
acceptance on this side of the Atlantic. There seems 
to be no reason why the term “histology ’’? should 
be displaced by this more modern word. Though, 
however, we may take exception to the title of the 
book, we are not disposed to regard other than 
favourably the work: itself. 
The study of this book leads to some reflection as 
to the methods by which instruction in histology can 
most advantageously be given. Manuals of instruc- 
tion are perhaps generally written so as to act as a 
complement to the teacher’s personal directions. 
This book, however, will replace the teacher himself. 
The directions given are so precise and simple as 
probably to be sufficient to furnish an effective guide 
to a student with practically no previous training in 
microscopic work. The question is, however, 
whether there are not disadvantages in this 
NO! MOG5 VOL s 5] 
The defect seems to be that a student using such a 
book may not have enough scope for his ingenuity 
and resource. It certainly fails to give much 
stimulus to a student’s power in the elaboration of 
new methods. But as the book is intended by the 
author primarily for the beginner, and as probably 
most students using it will adopt it simply to assist 
them in acquiring a competent knowledge of histo- 
logical methods without any intention of making 
use of them in later research, it must be stated that, 
so far as this objective is concerned, the book is 
worthy of the highest praise. 
The general arrangement of the work has no 
markedly novel features, but the expositions of the 
methods recommended are admirably clear. The 
smallest details of procedure are carefully marshalled, 
and the student is generally left without any oppor- 
tunity of making a mistake. But the instruction 
afforded is not simply telling the student how the 
methods are to be carried out; there are added, and 
this is one of the distinguishing features of the 
work, explanations of the possible reasons why 
occasionally failure may occur, and remedies for 
such failures. The author hopes that three classes 
of workers may be benefited by its use. The student 
in class or the independent individual worker will 
doubtless profit, but we hesitate to think that a book 
can be at the same time valuable as an instruction 
manual for elementary classes and as a general refer- 
ence book for the teachers of those classes. 
The crucial test of the value of the work must 
necessarily consist in the actual experiment of using 
it in class. We venture to think, however, that the 
volume will react to this test in a most successful 
manner. 
Elementare kosmische  Betrachtungen iiber das 
Sonnensystem und Widerlegung der von Kant 
und Laplace aufgestellten Hypothesen iiber dessen 
Entwickelungsgeschichte. By Prof. Gustav Holz- 
muller. Pp. v+98. (Leipzig: B. G. Teubner, 
1906.) Price 1.80 marks. 
Tus little boolk, in which is summarised the essential 
parts of a series of lectures given at various times, 
is another praiseworthy attempt to make the results 
of mathematical analysis available to those who have 
not received the necessary preliminary training. 
How far the author has been successful in conveying 
precise information to this class it is difficult to 
judge. As a rule, it would appear that those who 
do read such books do not stand in need of the 
elementary treatment offered, while those for whom 
the book is intended fail to grasp the nature of the 
demonstration. The author discusses some of the 
ordinary dynamical problems connected with falling 
bodies, and also Kepler’s laws, as resulting from 
the operation of a central force. He adds some re- 
marks on perturbations and tidal phenomena, but 
these sections are necessarily of the most sketchy 
character. There is a very good chapter on the 
present condition of the sun, written in a popular 
manner, and in which the author introduces some 
interesting topics; but here, as in other parts of the 
book, we would willingly have been spared the 
quotation of such big numbers, inserted, apparently, 
with the view of arresting attention. Finally, Prof. 
Holzmiuller examines the data on which rests the 
acceptance of the nebular hypotheses as developed by 
Kant and Laplace. We are not disposed to quarrel 
with his conclusions, which may be stated thus. 
The hypotheses set up by these philosophers to ex- 
plain the development of the solar system are in- 
adequate to explain the past history, and furnish 
unsatisfactory guides for the future. They cannot 
method. | be regarded as a contribution to exact science, but 
