On the Composition of Animals slaughtered as Human Food. 295 



and less than 1 per cent, of mineral matter. The increase over the 

 last few months of high feeding, of pigs fed for curing, will doubtless 

 contain a higher per-centage of both fat and total dry substance, and 

 a lower one of both nitrogenous compounds and mineral matter, than 

 that of the younger and more moderately fattened animal. 



As a general result, it appears that about l-ths of the gross increase 

 in Uve- weight, of animals feeding liberally for the butcher, will be 

 dry or solid matter of some kind. About |^rds of the gross increase 

 will be dry fat ; only about 7 or 8 per cent, of the gross increase 

 (and scarcely more than ^uth of the total dry substance) will be 

 nitrogenous compounds; and seldom more than 1^, and frequently 

 less than 1 per cent, mmeral matter. 



In the case of most of the sheep, and of all the pigs, the com- 

 position of whose increase was estimated, the amounts of mineral 

 matter, of nitrogenous compounds, of non-nitrogenous organic sub- 

 stance, of total dry substance, and sometimes of fat, which were 

 consumed during the fattening period, were determined ; so that the 

 means are at command for studying the quantitative relation of the 

 constituents estimated to be stored up in the mcrease, to those con- 

 sumed in the food which produced it. 



Taking first the proportion of each class of constituents stored up 

 for 100 of the same consumed, it is concluded, that in the case of 

 sheep, liberally fed on a mixed diet of dry and succulent food, the 

 increase of the animal will perhaps generally carry off less than 3 per 

 cent, of the consumed mineral matter — somewhere about 5 per cent, 

 (varying according to the proportion in the food) of the consumed 

 nitrogenous compounds, and about 10 parts of fat for 100 non-nitro- 

 genous substance in the food; and lastly, that for 100 of collective 

 dry substance of food consumed, there will be, in sheep, about 8 or 

 9 parts of dry matter in increase stored up. 



The food of the fattening pig contained a much smaller proportion 

 of indigestible woody fibre than that of the sheep ; and it appeared 

 that the pig appropriated to its increase a much larger proportion of 

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

 the estimates for pigs, showed about 1 7 parts of dry substance of 

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

 Bumed. 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 

 siiowed, 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 ia 

 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- 

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



