354 



the organic constituents of its food than the sheep. The average of 

 the estimates for pigs, showed about 17 parts of dry substance of 

 increase stored up, for 100 of collective dry matter of food con- 

 sumed. For 100 of non-nitrogenous organic constituents in food, 

 about 20 parts of fat were stored up. Of nitrogenous compounds, 

 when the food consisted of about the usual proportions of the legu- 

 minous seeds and cereal grains, from 5 to 7 or 8 parts were stored 

 up for 100 consumed. When the leguminous seeds predominated, 

 the proportion of the consumed nitrogen stored up was less ; and 

 when the cereal grains predominated, it was greater. The estimates 

 showed, that on the average of the cases, there were 4 or 5 times as 

 much fat stored up in increase, as there was of fatty matter supplied 

 in the food. There was obviously therefore a formation of fat in 

 the animal body. 



Reckoning the amount of the respective constituents of increase 

 stored up, for 100 of the collective dry substance of the food con- 

 sumed, the general result was as follows : It appeared, that of the 

 about 9 parts of dry increase, in sheep liberally fed on corn or oil- 

 cake and succulent roots, for 100 of dry food consumed, about 8 

 parts were non-nitrogenous substance, that is, fat. There was there- 

 fore only about 1 part stored as nitrogenous and mineral matters 

 taken together. The average of the estimates showed the produce 

 of 100 of the collective dry substance of the consumed food of sheep 

 to be about, 0'2 part of mineral matter, 0*8 part nitrogenous 

 compounds, and 8 parts fat, stored up; leaving therefore about 91 

 parts to be expired, perspired, or voided. 



Taking the average of all the estimates of this kind relating to 

 pigs of the \7\ parts of dry increase for 100 of dry matter of food 

 consumed, about 15f parts were estimated as fat, rather more than 

 l^rd part nitrogenous substance, and an insignificant amount as 

 mineral matter. On this plan of calculation, therefore, there would 

 appear to be, in the case of fattening pigs, only from 82 to 83 parts 

 of food-constituents expired, perspired, or voided, for 100 of the 

 collective dry substance of food consumed. 



It is obvious that the ultimate composition of the dry substance 

 of increase must be very different from that of the 100 of dry sub- 

 stance consumed. This is strikingly illustrated in the case of the 

 fat. In most of the experiments with pigs, the fatty matter in the 



