112 ' PAUL’S TECHNICAL ANALYSIS. 
who covet only an amusing book, prettily illustrated, on sea- 
side animals, will find this volume to their taste. Professor 
Jones is a charming writer, and few men have a greater gift 
of conveying information in a clearer or more graceful 
style. 
Manual of Technical Analysis, a guide for the testing and 
valuation of the various natural and artificial substances 
employed in the Arts and Domestic Economy, founded upon 
the ‘Handbuch’ of Dr. P. A. Bolley. By Brnsamin 
Pavt, Ph.D. London: Bohn. 
In the examination of the structure and composition of 
the various natural substances used by man in the Arts and 
Domestic Economy, it is frequently necessary to use more 
than one instrument of investigation. Where chemical 
analysis fails the microscope succeeds, and where the micro- 
scope is valueless the chemical reagents will frequently esta- 
blsh facts of the first importance. It not uncommonly 
happens that these two means of investigation are necessary 
to arrive at correct conclusions. Substances which cannot 
be obtained in sufficient quantities to be analysed with the 
naked eye may be chemically manipulated with the greatest 
success under the microscope. It is on this ground that the 
microscope and chemical experiment frequently meet, and 
the investigator of nature and the man of business must 
appeal to both. 
This volume deals principally with the application of che- 
mistry to the testing of natural substances, but in doubtful 
cases the aid of the microscope is called in. Thus, in giving 
directions for the examination of milk, starch, vegetable 
and animal fibres, the results of microscopic research are 
presented. It is not, however, from this side of the question 
that the principal facts of the book are presented, but from 
the chemical side ; and we call the attention of our readers to 
it, as a volume full of information on facts which they will 
find of great service in those researches with the microscope 
which have an immediately practical end in view. 
