136 
NATURE 
[APRIL II, 1912 
sertation is the first of its kind in this country, 
but no serious student of agriculture, and parti- 
cularly of its relation to the trend of commer- 
cial and social development, will fail to derive 
profit from Mr. Rutter’s book. It represents 
an immense amount of painstaking work, such 
as can only be appreciated by one who has 
himself tried to reduce to some common denom- 
inator the scattered statistics and information 
about various countries, and it should find an in- 
terested public now that agriculture is being 
systematically studied and taught in the United 
Kingdom. Je 1D); 1ST. 
ACTUAL ELECTROCHEMISTRY. 
Applied Electrochemistry. By Prof. M. de Kay 
Thompson. Pp. xii+329. (New York: The 
Macmillan Co.; London: Macmillan and Co., 
Ltd., r9rr.) Price gs. net. 
HERE have been many books written on 
this subject, and they are apt to come 
under two heads, the purely scientific, in which 
the principles of modern clectrolytic theory Are 
discussed very fully, without much information as 
to their practical application; and the purely com- 
mercial, in which the various industries are de- 
scribed, with views of the various kinds of plants. 
A third variety might be included which discusses 
all sorts of processes, most of them never having 
had any real existence, the information and illus- 
trations being taken entirely from the rather 
imaginative patent literature of the subject. 
Dr. Thompson does not begin with an elaborate 
treatise on what is known as “theory ”—he as- 
sumes that the reader is well acquainted with the 
first principles; he merely refers to them, and 
utilises them and their formula as he needs them. 
He discusses first such subjects as electrochemical 
analysis. This chapter is a mere sketch, but a 
good sketch of the subject, which is now far too 
large to be treated so shortly. A reader would 
get a good idea of this sort of analysis from the 
book, but in order to utilise it he would have to 
study a special treatise. Electro-plating is treated 
very shortly, but in a refreshingly common-sense 
way. This common sense runs through the whole 
book. It is not necessary to give a list of the 
contents; it may be taken that the book gives a 
concise account in clear and scientifically accurate 
language of all the important electrolytic and 
allied processes in commercial use, and that it 
does not discuss all sorts of inventions that have 
been failures in practice. It is a great pity that 
such failures are not discussed as failures, the 
reasons of their non-success being given. These 
would be very valuable, but difficult to 
In science, both applied and unapplied, 
NO. 2215, VOL. &g| 
most 
give. 
people are far too reticent about failures, yet 
there is much to be learned from them. Dr. 
Thompson deals very fully with the electrolysis of 
salt in the wet way, and one of the most interest- 
ing chapters is that on ozone. Though there are 
books on ozone there is not much trustworthy 
information, and this chapter is very welcome. 
The book is American, with heavy American: 
paper but no aggressive American spelling. It 
has involved a great deal of literary work, and. 
references are always given. There can be little 
doubt that the amount of matter read and rejected. 
was greater than that utilised. The work is, in 
short, an admirable, intelligent account of the: 
electrochemical industry as it exists. 
J. SwiInBurNe. 
A TREATISE ON CHOLERA. 
Cholera and its Treatment. By Prof. L. Rogers. 
pp. xiv+236. (London: Henry Frowde and 
Hodder and Stoughton, 1911.) Price ros. 6d. 
net. 
HIS book is a complete treatise on cholera, 
containing all the essentials of the subject 
without being over-burdened with details which 
are of little practical importance. The first and 
second chapters deal with the history of cholera 
epidemics and their lessons, and the epidemiology 
of the disease. In chapter iii. the etiology and pro- 
phylaxis of the disease are discussed, and it com- 
mences with a description of the specific organism. 
of the disease, the comma bacillus of Koch, which 
the author fully accepts as the cause of cholera. 
In this section we should have been glad to see a 
somewhat fuller discussion of the significance of 
the various cholera-like comma bacilli which have 
been isolated during the last few years. The 
hypothesis of Emmerich that cholera is a condi- 
tion of nitrite poisoning is not accepted by the 
author. Prophylactic vaccination by means cf 
cholera vaccine is regarded as being of consider- 
able value, and the measures to be taken for the 
disinfection of infected wells are described. 
Chapter iv. deals with the clinical aspects of 
cholera and its diagnosis, chapter v. with the 
morbid anatomy and pathology. In the final 
chapter the treatment is discussed at some length, 
and to many this will be considered the most im— 
portant part of the book, for the author himself 
has contributed in no small measure to the rational 
treatment of this terrible malady. Dr. Rogers is 
entirely opposed to the purgation method except at 
the very early stage and before the onset of the 
typical watery evacuations, the ‘‘rice-water 
stools.”” Opium also has to be used with extreme 
caution. Injections of saline fluid, either per 
rectum, subcutaneously, intraperitoneally, or 
