HALF-HOURS WITH THE MICROSCOPE. 195 
arrangements. In the second book, the use of the micro- 
scope is described, and copious details given respecting the 
making of microscopical preparations; whilst in the third, 
we have a lengthened historical account of the instrument in 
all its forms, and of the state of comparative perfection at 
which it has now arrived. Every kind of accessory appa- 
ratus is also here described, and the utmost pains appear to 
have been taken to render this part of the work complete, 
and so far as we can perceive with success. 
The subjects of micro-chemical analysis, micrometry, 
microgoniometry, &c., the estimation of the absolute and 
specific weights of microscopic objects, their refractive and 
polarizing properties, &c., are fully and ably treated. 
Microscopic drawing and micro-photography also find a 
place. 
In fact, nothing seems to have been omitted to render the 
present one of the most complete and useful works yet pub- 
lished on the subject of the microscope—and as such we 
recommend it to our readers. 
Half-hours with the Microscope ; being a popular guide to the 
use of the microscope as a means of amusement and 
instruction. Illustrated from Nature, by Turren West. 
Pp. 83. 
Tus unpretending little book is really one of considerable 
worth, and will be found interesting to a large class of 
Incipient microscopic observers, who use their instrument 
more for the purposes of rational amusement than with any 
actual scientific object. Its great value depends upon the 
plates, which are filled to repletion with accurate and well- 
drawn figures of a vast number of objects culled with much 
discrimination, from almost every department of natural 
history. To say that the figures have been executed by 
Tuffen West is to say that they are good and faithful 
representations of what they profess to delineate—and as we 
presume the objects were themselves selected by that gentle- 
man, his judgment appears to have been as well exerted in 
that selection as his skill in the representation of the things 
selected. 
The text is succinct and clear, giving in as few words as 
possible a description of the various objects represented in 
