64 PRINCIPLES OF ANIMAL NUTRITION. 
Kéhler * has investigated the elementary composition of the 
muscular tissue of cattle, sheep, swine, horses, rabbits and 
hens. The material was prepared with much care, the fat being 
removed as fully as possible by prolonged extraction with ether. 
The residual fat which cannot be removed in this way was deter- 
mined by Dornmeyer’s digestion method,t and a corresponding 
correction made in the analytical results. The following are his 
averages for the fat- and ash-free substance: 
Heat of 
. of n, rogen, |Ni n,| Sulphur, | O: 5 mbustion 
Sanples. Por Gout, oe Cent. Dor Cont. Per Cent. Per Cent. ‘per oer 
Cattle....... 4 52.54 7.14 16.67 | 0.52 + 23.12 | 5.6776 
Sheep 2 52.53 7.19 16.64 0.69 22.96 5.6387 
Swine...... 2 52.71 %.17 16 60 0.59 22.95 5.6758 
Horse. ...... 3 52.64 7.10 15.55 0.64 24.08 5.5990 
Rabbit...... 2 52.83 7.10 16290 || sccieses ware | aco os aerners 5 6166 
Hen § o-g sci 2 52.36 6.99 16.88 0.50 23.28 5.6178 
All the samples were tested for glycogen, but only traces were 
found, except in the horseflesh, for the two samples of which an 
average of 3.65 per cent. was obtained, a result which accounts for 
the low figure for nitrogen. 
In the classic investigation by Lawes & Gilbert } into the com- 
position of the whole bodies of animals, determinations were made 
of the total dry matter, the ash, the fat, and the total nitrogen. 
From these data Henneberg § has compared the total amount of 
dry matter other than ash and fat with the total amount of nitro- 
gen. His results in a slightly altered form are given in the table 
opposite. 
The average nitrogen content is 16.21 per cent. Lawes & Gil- 
bert extracted the fat with ether and hence, as above noted, the 
residue was not absolutely fat-free. Kdhler’s average results for the 
* Zeit. physiol. Chem., 81, 479. 
y Arch. ges. Physiol., 65, 102. 
Phil. Trans., 1859, II, 498. 
§ Neue Beitriage, etc., p. x. 
