752 
REVIEW. 
Quid sit pulchruin, quid turpe, quid utile, quid non.—Hon. 
Organic Chemistry m its applications to Agriculture and Phy¬ 
siology, By Justice Liebig, M.D., Ph.D., F.R.S., M.R.S.A., 
translated hy Lyon Playfair, Ph.D. 
A WORK replete with interesting matter. In the preface the 
author informs us that, at one of the meetings of the chemical section 
of the “ British Association for the advancement of Science,” the 
honourable task of preparing a report upon the state of organic che¬ 
mistry was imposed upon him, and this work is a part of that 
report. He, farther on, observes, that since the time of the immor¬ 
tal author of the Agricultural Chemistry,” no one has occupied 
himself in studying the application of chemical principles to the 
growth of vegetables and to organic processes. The path marked 
out by Sir Humphry Davy he has endeavoured to follow, because 
he based his conclusions only on that which was capable of inquiry 
and proof. This is the path of true philosophical inquiry, which 
promises to lead us to truth—the proper object of our research. 
The work is divided into two parts. The first is devoted to the 
examination of the matters which supply the nutriment of plants, 
and of the changes which these matters undergo in the living 
organism. The second treats of the chemical processes which 
effect the complete destruction of plants and animals after death, 
usually described as fermentation, putrefaction, and decay, or ere- 
macausis. It opens with some useful truisms. 
“ The continued existence of all living beings is dependent on the reception 
by them of certain substances which are applied to the nutrition of their 
frame. An inquiry, therefore, into the conditions on which the life and growth 
of living beings depend, involves the study of those substances which serve 
them as nutriment, as well as the investigation of the sources whence these 
substances are derived, and the changes which they undergo in the process of 
assimilation. 
“ The primary source whence man and animals derive their means of growth 
and support is the vegetable kingdom. Plants, on the other hand, find new 
nutritive material only in inorganic substances.” 
After reviewing the constituent elements of plants—carbon, hy¬ 
drogen, and oxygen—and shewing the relative proportion they 
bear to each other, thus giving rise to the different proximate prin¬ 
ciples, he observes of nitrogen, that, estimated by its weight it forms 
only a very small portion of plants, but it is never entirely absent 
from any part of them. Even when it does not absolutely enter 
into the composition of a particular part or organ, it is always to be 
found in the fluids which pervade it. 
