342 



Sir J. B. Lawes and Dr. J. H. Gilbert. [June 21, 



VIII. "Supplement to former Paper entitled — 'Experimental In- 

 quiry into the Composition of some of the Animals Fed and 

 Slaughtered as Human Food,' — Composition of the Ash of 

 the Entire Animals, and of certain Separated Parts." By 

 Sir John Bennet Lawes, Bart., LL.D., F.R.S., F.C.S., and 

 Joseph Henry Gilbert, Ph.D., LL.D., F.R.S., V.P.C.S. 

 Received June 11, 1883. 



(Abstract.) 



In a former paper ("Phil. Trans.," Part II, 1859) the authors had 

 given the actual weights, and the percentage proportion in the entire 

 body, of the individual organs, and of certain more arbitrarily 

 separated parts, of 326 animals — oxen, sheep, and pigs — in different 

 conditions as to age, maturity, fatness, &c. They called particular 

 attention to the wide difference in the proportion by weight of the 

 stomachs and intestines in the three descriptions of animal ; the pro- 

 portion of stomach and contents being ^ery much the highest in oxen, 

 considerably less in sheep, and little more than one-tenth as much in 

 pigs as in oxen. On the other hand, the intestines and contents con- 

 tributed a less proportion to the weight of the body in oxen than in 

 either sheep or pigs ; the percentage by weight in pigs being nearly 

 twice as high as in sheep, and more than twice as high as in oxen. 

 With these very characteristic differences in the proportion of the 

 receptacles and first laboratories of the food, the other internal organs 

 collectively, as also the blood, contributed a pretty equal proportion 

 by weight of the entire body, in the three descriptions of animal. 



Ten animals had been selected for the determination of the chemical 

 composition, namely — a fat calf, a half-fat ox, and a fat ox ; a fat 

 lamb, a store sheep, a half-fat sheep, a fat sheep, and a very fat sheep ; 

 a store pig, and a fat pig. In these, in the collective carcass parts, in 

 the collective offal parts, and in the entire bodies, the total nitrogenous 

 substance, the total fat, the total mineral matter, the total dry sub- 

 stance, and the water, were determined ; and the results were recorded 

 and discussed in detail. 



It was shown that, as the animal fattened, the percentage of nitro- 

 genous substance decreased considerably, whilst that of the fat and of 

 the total dry matter increased in a much greater degree. It was 

 estimated that the portions of well fattened animals which would be 

 consumed as human food would contain three, four, and even more 

 times as much fat as dry nitrogenous substance ; and comparing such 

 animal food with wheat-flour bread, it was concluded that, taking into 

 consideration the much higher capacity for oxidation of a given weight 



