308 THE AMERICAN MONTHLY | Nov 
ago, he has constantly worked up new material and the 
frequency of editions suggeststhat the type must be kept 
standing in Ithaca and a fresh set of proofs sent up the 
hill very frequently foremendation and expansion. This 
thrift is very commendable in a constantly changing and 
growing field of learning. Unfortunately, the old edi- 
tions quickly outlaw and second-hand copies are worth- 
less. 
Comparison with Carpenter is hardly to be thought of, 
and yet having searched Carpenter’s very latest edition 
for a description of the ever-mentioned “Society Screw,” 
in vain, we turn to page 64 of Gage’s Manual and find the 
formula exactly and properly quoted. 
For the general microscopist, we conceive that Carp- 
enter answers every purpose and is indispensable. But 
for students the price is important. Carpenter costs 
$8.00 and Gage perhaps $1.50. Its data is all easily 
available through a completes and skillful index. 
The frontispiece shows the names of all the 17 parts 
of a microscope in such a way as to immediately inform 
a beginner of what the instrument is composed. The 
other 228 cuts are equally clearandinstructive. A dozen 
or more instruments of different make are shown inelud- 
ing both domestic and the better foreignones. Weshall 
refer later to other matter contained in the book, 
MISCELLANEOUS. 
ASPLANCHNA.—-Several species have interesting jaws and 
teeth. The jaws are dissolved out with caustic potash and 
mounted separately. The jaws are from 100 to 150 mic- 
rons long, (25,000 microns make one inch). 
Liquip AMBER.—Liquid amber styraciflua is spoken of 
as storax, balsamium styracis, styrax liquidée and Flussi- 
ger storax. It has a high refractive quality. It is used 
Se a a 
