192 
lieuig's organic chemistry. 
some other purpose, and this other is the formation of fat. 
This is evinced in the feeding of animals on substances con- 
taining nitrogen. They do not become fat, although their 
bulk is increased by the expansion of the organic tissues ; 
whereas, in corn-fed animals, the nitrogen being deficient, 
the fat is formed in excess. An examination of the compo- 
sition of fatty bodies will show how this may take place. 
Gum, sugar, &c, and fats, differ in composition, principally 
in regard to the amount of oxygen; the carbon and hydro- 
gen being in nearly the same ratio in all. This being the 
case, to convert starch, &c, into fat it is only necessary to 
abstract oxygen, together with a small amount of carbon. 
Here, then, the deficiency in absorption of atmospheric 
oxygen, gives rise to the abstraction of oxygen from the 
food, and the subsequent conversion of the food, or of the 
organism itself, into principles deficient in that element. 
It follows, from these views, that the food of man " may 
be divided into two classes: into nitrogenized and non-ni- 
trogenized." " The former may be called the plastic ele- 
ments of nutrition ; the latter, elements of respiration" 
Among the former, are vegetable albumen, fibrine, and ca- 
seine, with animal flesh and blood. Among the latter, fat, 
starch, gum, sugar, pectin, bassorin, alcoholic and fermented 
liquors. 
The remainder of the work is devoted to an examination 
of the chemical processes engaged in the production of the 
secretions, bile, urine, &c, and the nervous organism, ac- 
companied by copious analyses and calculations; and in 
speculations on the laws of the phenomena of motion, to- 
gether with the theory of disease and respiration. These 
we are compelled to pass over; and, in concluding would 
remark, that the terse and sententious nature of the author's 
style, creates an appearance of obscurity, requiring very 
close attention, in some parts, to ascertain the true meaning. 
R. B. 
