, 
May 20, 1915] 

NATURE 
SPSL 

and Senderens started their epoch-making  re- 
searches in 1897. These chemists found that 
finely divided metals other than platinum, namely, 
iron, cobalt, copper, and especially nickel, could 
be used with marked success as catalysts in reac- 
tions of this type, and the catalogue of Poulenc 
success which has attended their work. 
It is stated that the nickel most suitable for the 
purpose is obtained by reducing the oxide by 
hydrogen at a temperature of between 270° and 
300°, but no one who has worked on this subject 
ean have failed to experience the extraordinary 
differences in the activity of the metal produced 
under various experimental conditions, and it is 
therefore not surprising that no great technical 
use has been found for the process until within 
comparatively recent years. 
The fact that the liquid or unsaturated fats 
the olein type are unsuited for the purposes 
soap-making, as well as for the production 
edible fats, has caused numerous experiments to 
be made with the object of converting these sub- 
stances, either wholly or partially, into the satur- 
ated or hard fats of the stearin series. As early 
as 1875 Goldschmidt showed that oleic acid could 
be reduced to stearic acid by phosphorus and 
hydriodic acid at a high temperature, and, indeed, 
this process, or a modification of it, was applied 
on the industrial scale at about this time, but the 
method was not successful, and it was not until 
W. Normann, in 1903, took out a patent for a 
“process for converting unsaturated fatty acids 
or their glycerides into saturated compounds ”’ 
that the Sabatier and Senderens’ method was 
applied to the saturation of unsaturated fats and 
the tremendous possibilities of the process from 
an industrial point of view became evident. 
The patent of Normann was obviously bad, and 
it was rendered invalid in 1913, as the result of 
an action between Joseph Crosfield and Sons, 
Ltd., and Techno-chemical Laboratories, Ltd. 
In the book under review, the first two chapters 
are devoted to a description of all the various 
processes which have been used for the purpose 
of effecting hydrogenation, and it is in this por- 
tion that the author seems to have erred on the 
side of over-elaboration. The point had evidently 
occurred to him, because, in his introduction he 
states that “The observations and opinions of 
many minds have been brought together. Some 
of these views obviously are sound, others are 
open to grave doubt, and still others are of a con- 
tradictory or. polemical nature. Whether or not 
in the treatment of this material to carry through 
a vein of critical comment was a problem which 
confronted the author.” That he decided not to 
introduce this vein of criticism and to give the 
NO: 2377; VOL. 95] 
value of his experience in discriminating between 
the various processes is, we think, a matter which 
will be regretted by the average reader. As it is, 
one almost feels inclined to say that some of the 
methods described could scarcely have been ex- 
| pected to yield satisfactory results even by their 
Fréres, of Paris, bears witness to the practical | 


discoverers, and the reader who is not an expert 
will arrive at the conclusion that there are some 
fifty different ways by which hydrogenation may 
be accomplished, and that all of them are of equal 
importance. To the expert, however, who is able 
to sift grain from chaff, this section will be of 
the greatest service. 
The same criticism applies to the next section 
of the book, which deals with the various kinds 
of catalysers which have been used. This section 
occupies two chapters, and is succeeded by an 
admirable account of nickel carbonyl, followed, 
in chapter vi., by an interesting account of the 
work of Paal and others on the use of the rare 
metals in the colloidal state as catalysts. Chap- 
ter villi. deals with the analytical constants of 
hydrogenated oils, and the two succeeding chap- 
ters contain a description of the methods by 
which these oils may be converted either into 
edible fats or into soap. The last nine chapters 
of the book, some hundred pages in all, deal 
with the various methods which have been devised 
for the preparation of hydrogen. ‘This section is 
treated in a most exhaustive manner, and the 
influence of impurities in the hydrogen, acting 
either as poisons to the catalysts or as substances 
injurious to the oils, are discussed. The book 
ends with an appendix containing an account of 
the recent litigation over the Normann patent. 
This excellent treatise is well illustrated by 
some 145 photographs and drawings both of 
scientific apparatus and of plant. The admirable 
manner in which the author has emphasised the 
scientific basis of the technical processes which 
he has described causes it to be a noteworthy 
addition to our literature on specialised organic 
chemistry. Ye 18g 10 

A TEXT-BOOK OF EFFICIENCY. 
Fundamental Sources of Efficiency. By Dr. F. 
Durell. Pp. 368. (Philadelphia and London: 
J. B. Lippincott Company, 1914.) Price ros. 6d. 
net. 
O many it once came as a shock to hear 
te that the great Mach laid stress on the 
economy of thought in science. It seemed as 
though science were brought into too close ana- 
logy with much more mundane kinds of human 
activity. But in this book the study of almost 
every conceivable kind of activity, including 
scientific activity, is made from the abstract 
