No. 421.] NOTES AND LITERATURE. 75 
in. The strong mineral acids in normal solutions are by no means 
completely dissociated in all cases (p. 53). A “normal solution ” 
as defined in botanical literature should conform to the chemical 
usage (p. 51). Unfortunately, in a number of instances botanists 
have failed to be thus exact in the use of terms, and confusion is 
likely to follow. These matters will doubtless correct themselves in 
later editions of the book under discussion. 
The chapter dealing with the composition of the plant body, writ- 
ten by Mr. J. E. Kirkwood and Dr. W. J. Gies, introduces the 
beginner to the methods of detecting and estimating many of the 
more important substances that may be extracted from plants. This 
chapter will probably prove very useful, since it furnishes in clear, 
brief terms much information to which the student will be glad to 
refer often. The chapters dealing with the chemical changes taking 
place in the plant, with growth and with reproduction, call forth 
much by way of commendation. 
In view of the fact that the book is intended to contain “ details 
of experimental methods suitable for the exact analyses requisite 
in research work,” it demands notice as a laboratory guide. The 
experiments are closely interwoven throughout the book with the 
discussion of the various phases of the subject which they illustrate. 
Generally speaking, the experiments are abundant and well chosen, 
and the directions for work are couched in clear terms. In the man- 
ner of arranging this matter, one might perhaps see some grounds 
for question. The juxtaposition of experiment to principle illustrated 
aids a possible shrewd guess on the part of the student occasionally, 
but the author has generally avoided undesirable suggestion in 
describing the experiments. Of course, this intermingling of discus- 
sion and experiment makes the book more difficult of use as a work 
of reference. 
As a whole the illustrations are good, whether original or bor- 
rowed. ‘An occasional exception may be noted (Fig. 134). 
An appendix contains numerical data of use to the laboratory 
student. Tables for converting units of various kinds into those of 
other systems, densities of gases, expansion of air at different tem- 
peratures, and an abridgment of Pfeffer’s table of osmotic values 
may be mentioned. : 
The book has so many excellencies that it is entitled to a wide 
use, and the occasional errors will be remedied as later editions call 
the author's attention more critically to his text. RET 
. 
