SCIENCE AND INDUSTRY. 
of great interest and of ever-increasing importance is that on hardening of fats, 
or the hydrogenation (proper) of oils, pp. 101-110. We also find interesting 
information on the preparation of synthetic rubber by using colloidal Na in an 
atmosphere of COz, and the vuleanization of rubber by catalysts like glycerol 
(Swiss patent 1916). The table of catalysts, on p. 194, would be much improved 
if a list of the catalyses they produce were also added. 
The book ‘is a very readable and useful work on a difficult and obscure subject, 
and all students of chemistry must in the future possess a good knowledge of 
catalysis. 
Natural Science is a subject which a man cannot learn 
by paying for teachers. He must teach it himself, by patient 
observation, by patient common sense. And if the poor man | 
is not the rich man’s equal in those qualities, it must be his 
own fault, not his purse’s, 
—CHARLES KINGSLEY. 
