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One of the most important applications which can be made of a 

 knowledge of the composition of the animals which constitute the 

 chief sources of our animal food, is to determine the main points of 

 distinction between such food and the staple vegetable substances 

 which it substitutes or supplements in an ordinary mixed diet. 



By the analysis of some of the most important animals fed and 

 slaughtered as human food, it was found that the entire bodies, even 

 when in a reputed lean condition, may contain more dry fat than 

 dry nitrogenous substances. Of the animals " ripe " for the butcher, 

 a bullock and a lamb contained rather more than twice, a moderately 

 fat sheep nearly three times, and a very fat sheep and a moderately 

 fat pig about four times as much dry fat as dry nitrogenous matter. 

 Of the professedly fattened animals analysed, a fat calf alone con- 

 tained rather less fat than nitrogenous compounds. 



It was estimated, that of the whole nitrogenous substances of the 

 body, 60 per cent, in the case of calves and oxen, 50 per cent, in 

 lambs and sheep, and 78 per cent, in pigs, would be consumed as 

 human food. Of the total fat of the bodies, on the other hand, it 

 was supposed, that in calves and lambs 95 per cent., in oxen 80 per 

 cent., in sheep 75 per cent., and in pigs 90 per cent, would be so 

 applied. 



Assuming the proportional consumption of the fat and nitrogenous 

 compounds to be as here estimated, there would be in the fat calf 

 analysed 1-| time, in the fat ox 2f times, in the fat lamb, fat sheep, 

 and fat pig nearly 4^ times, and in the very fat sheep 6 times as 

 much dry fat as dry nitrogenous or flesh-forming constituents con- 

 sumed as human food. 



It would perhaps be hardly anticipated, that in the staple of our 

 meat-diet, to which such a high relative flesh-forming capacity is 

 generally attributed, there should be found such a high proportion 

 of non-flesh-forming to flesh-forming matter as above indicated. 

 The result of such a comparison as present knowledge permits in 

 regard to the same point between the staple of our animal food and 

 the more important kinds of vegetable food, will certainly not be 

 less surprising 



Of the staple vegetable foods, wheat-flour bread is, at least in this 

 country, the most important. It will be interesting, therefore, to 

 contrast with this substance the estimated consumed portions of the 



