DECEMBER 18, 1913] 
NATURE 
447 
and R. Griessbach. The chapters on oxidation and 
than 20 pages each, and many other technical 
processes, such as the manufacture of soap, starch, 
and paper, are treated in the same detailed 
fashion. We have no desire to underrate the value 
of a book which devotes the greater part of its 
space to technology. On the contrary, the excel- 
lent and copious illustrations of plant and ma- 
chinery, the clear exposition of the processes and 
the carefully compiled statistics will appeal to 
many students of organic chemistry, who will look 
in vain for practical information of this character 
in the ordinary text-book. 
But they must bear in mind that the description 
of operations, which are often merely mechanical 
and in no sense chemical, cannot replace the prin- 
ciples of the science, which should be carefully 
studied and assimilated in advance. 
Whilst, therefore, strongly recommending the 
book to the English student, we must warn him 
that he cannot afford to neglect the theoretical 
side, and that details of any technical process, 
however elaborate, will not make him a techno- 
logist. We must also point out that he is placed 
at some disadvantage by reason of the book having 
been written by an Italian for Italians. The appar- 
atus and methods of technical analysis are often 
not those recognised as standard methods in this 
country. Moreover, the rather indiscriminate 
mixing of English and foreign weights and 
measures is a little confusing. 
Thus, we are told on page 69 that in desulphur- 
ising petroleum 4500 kilos of iron oxide are mixed 
with 200 tons of petroleum; on page 72 it is stated 
that the value of Bakoum petroleum is about 
7s. 2d. per quintal; on page 532 the quantity of 
tar treated in England is given in tons; whilst that 
of creosote oil extracted from it is put down in 
hectolitres. Moreover, the ton is the metric ton 
{1000 kilos) and not the English weight. If, in 
a future edition, the technology could be edited 
by the translator and English money, weights, and 
measures introduced so as to conform with 
English practice, the utility and interest of the 
volume for English readers would be greatly en- 
hanced. As it is, the volume is a distinct addition 
to chemical literature, and the translator, Mr. 
T. H. Pope, may be congratulated on the ability 
with which he has carried out a task which must 
have entailed an enormous amount of assiduous 
application. 
(5) Dr. Béttger’s qualitative analysis based on 
the ionic theory is too well known to need a special 
notice. The present volume is the third edition. 
The principal changes are corrections and emenda- 
tion of the text and the addition of microchemical 
reactions, which have been specially studied for 
the new edition by his collaborators, R. Heinze 
NO. 2303, VOL. 92] 
reduction have been thoroughly revised, and a 
section on autoxidation has been added. 
Qualitative analysis is a branch of practical 
chemistry which is so frequentiy presented in the 
form of small books adapted for examination use, 
that it is a satisfaction occasionally to meet with 
one in which the subject is raised to something like 
its proper dignity; and no justification for such a 
book is needed. It is interesting, nevertheless, to 
read Dr. Béttger’s apologia; for it expresses views 
in which many teachers of chemistry will entirely 
concur. The following is a rough translation :— 
“The preference for short and elementary text- 
books, whereby a working mastery of analytical 
technique can be achieved, stands in direct oppo- 
sition to the views attached to other branches of 
study in institutions for higher education and to 
the system of instruction current in the higher 
secondary schools. It is obvious that so large 
a mass of material as that included in analytical 
chemistry cannot be mastered in the short time 
devoted to the study of qualitative analysis. But 
it is unquestionably more important and educative 
for the beginner to learn to use at the outset a 
book which may act as a guide in his later re- 
searches, even if it involves a little more labour, 
than to study analysis from elementary books 
which must fail him when more difficult problems 
present themselves.”’ 
(6) The volume under review is on chemistry 
and crystallography, and is one of nineteen, which 
include mathematics, the natural sciences, and 
medicine. They form together one section of a 
series, which, when completed, will comprise up- 
wards of sixty volumes dealing with what is 
termed “Modern Culture.” 
The present volume contains an account of the 
development of different branches of chemical 
science, such as inorganic, organic, and physical 
chemistry, thermochemistry, photochemistry, elec- 
trochemistry, physiological chemistry, agricultural 
chemistry, and crystallography, all within the 
space of 650 pages. 
The names of the contributors are sufficiently 
well known in the chemical world to ensure that 
each subject is adequately treated so far as space 
permits. E. von Meyer has written a general, 
historical introduction, and among other writers 
are Wallach, Luther, Nernst, Le Blanc, Kossel, 
Witt, &c. Each subject is introduced by a brief 
historical review, with an account of its later pro- 
gress and development. The book is, in short, a 
history of the science brought down to modern 
times. 
It is not quite easy to determine for what class 
of readers the book is intended. It is far beyond 
