326 COMPOSITION AND NUTRITIVE VALUE OF COTTON-CAKE. 
As decorticated cotton-cake is likely to be extensively used 
for feeding purposes, I have thought it advisable to submit 
the mineral constituents which it furnishes on burning; to a 
detailed examination. 
The following results were obtained in my laboratory 
by my friend and pupil Mr. Gardner, of Shrewsbury, on 
analysing the ash prepared from several samples of decorti¬ 
cated cake : 
Average Composition of the Ash of Decorticated Cotton-cake. 
Potash .... 
. 39 045 
Soda .... 
none. 
Chloride of sodium 
none. 
Lime .... 
. 3750 
Magnesia .... 
. 13-500 
Oxide of iron 
. 1-530 
Phosphoric acid 
. 39-649 
Sulphuric acid 
•930 
Carbonic acid 
•362 
Soluble silica 
. 3252 
Insoluble silicious matter (sand) 
. 17-706 
99-724 
Like other oily seeds, cotton-seed contains, it will be 
a considerable quantity of phosphate of magnesia. In addi¬ 
tion to these compounds it contains phosphate of lime and 
phosphate of potash, and other salts of potash. 
The proportion of phosphoric acid in cotton-cake ash is 
very large, and that of potash likewise is considerable. Soda 
does not enter into the composition of the ash. For the 
purpose of supplying animals with bone-materials, it is a 
very valuable kind of food. 
Conclusion. 
The principal points of interest, in reference to cotton-cake, 
are collected together in the following short summary : 
1. The best cotton-cake is richer in oil and albuminous 
(flesh-forming) compounds than linseed-cake, but contains 
less mucilage and other respiratory constituents. 
2. The mineral portion of cotton-cake resembles closely 
in composition that of linseed and other oil-cakes. Like 
the ash of all cakes, it is rich in earthy and alkaline phos¬ 
phates, and well adapted to supply animals with bone-mate¬ 
rials. 
3. As far as the indications of chemical analysis can be 
depended on, the best decorticated cotton-cake possesses 
about the same nutritive value as linseed-cake. 
