ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
371 
(6) Miscellaneous. 
Microchemical Analysis.* — The publication of this volume of Prof. 
Behrens marks a decided advance in a method of qualitative analysis 
which bids fair to rival and in many cases to supersede the old blow- 
pipe processes. To the mineralogist and petrologist, who is often com- 
pelled to work on very limited amounts of material, these microchemical 
methods of analysis have become almost indispensable. 
The two best known previous works on the subject, by Haushofer 
and Element and Renard, in which the attempt is first made to give 
distinctive microchemical reactions for each element, leave much to be 
desired in the case of the distinction between many closely .related 
elements. In the present case it can hardly be said that these difficulties 
have received their complete solution, but, as the author implies, the 
subject is still in its infancy, and the main object of the book is to give 
a short review of the rudiments of microchemical analysis and of the 
progress which has been made within the last ten years, and at the same 
time to point out the problems which need solution in the further 
development of this new branch of chemistry. 
The book is divided into two parts. In the first, after a short 
Historical introduction, the author states the general principles which 
have guided him in the choice of the microchemical reactions w'hich 
are given for each element later on. Then follows a description of the 
apparatus and a list of the reagents used. With regard to the Micro- 
scope, any instrument which allows of magnifications from 50 to 200 
times, and is provided with Nicol prisms and arrangements for measuring 
angles of crystals, and extinction angles, and for the observation of the 
optic axes in convergent polarised light, can be used. The author par- 
ticularly recommends for microchemical work the Microscope (7 5) of 
Seibert. 
The greater portion of the first part of the book (100 j}p.) is occupied 
with the description of the different microchemical reactions for each 
element. The second part treats of the systematic use of these reactions 
for the investigation of mixed compounds, such as minerals, rocks (in 
section and in powder), alloys, &c. 
Manual of Microscopy, f— This book is what it professes to be, a 
guide to scientific microscopy, provided that we are content to know 
only of the instruments, workers, and methods of Germany. Although 
aiming at meeting the wants of schools of medicine and pharmacy, and 
giving all the information required in practical microscopical work by 
the student of biology, whether in botany or zoology, the student ir 
given no information that would lead him to suppose that any othet 
nation beside Germany had ever devised or employed a Microscope, or 
added anythiug to our knowledge of microscopic biology. 
The book is admirably arranged and carefully written ; it is accurate, 
and in some points exhaustive ; but to the practical microscopist who 
has followed the history of optical theory and practice during the last 
* * Anleitung zur Mikrocliemischen Analyse,’ von H. Behrens, Hamburg and 
Leipzig, 1895, 8vo, 221 pp., 92 figs. 
t • Daa Mikroskop. Ein Leitfaden der wissenscliaftlichen Mikroskopie,’ von Dr. 
A. Zimmermann, Leipzig and Wien, 8vo, 1895, 381 pp., 231 figs. 
2 B 2 
