298 Royal Society : — 



ding from this list the blood, which was more than ^rd of a per cent, 

 lower in amount in the pigs than in the other animals, the sums of 

 the per-centages of the other parts enumerated would agree even 

 much more closely for the three descriptions of animal. 



With regard to the influence of progression in maturity and fatness 

 of the animal, upon the relative development of its several parts, the 

 results showed, that the internal organs and other oflfal-parts pretty 

 generally increased in actual weight, as the animals passed from the 

 lean to the fat, or to the very fat condition. The per-centage prO' 

 portion to the whole live-weight, of these offal-parts, as invariably 

 diminished as the animals matured and fattened. The carcasses, on 

 the other hand, invariably increased, not only in actual weight, but 

 iu proportion to the whole body. 



The conclusion is, that in the feeding or fattening of animals, the 

 apparatus which subserves for the reception and elaboration of the 

 food does not increase commensurately with those parts which it is 

 the object of the feeder to store up from that food. These parts are 

 comprised in the "carcass " or frame-work, with its covering of flesh 

 and fat. Of the carcasses which thus constitute the greater part of 

 the increase, the nitrogenous portions increase but little, whilst the 

 fat does so in very much larger proportion. Of the internal parts, 

 again, it is also theybi^ which increases most rapidly. 



The maturing process consists, then, in diminishing the propor- 

 tional amount in the whole body, of the collective muscles, tendons, 

 vessels, fleshy organs, and gelatigenous matters — the motive and func- 

 tional, or so to speak, working parts of the body — the constituents of 

 which alone, can increase the amount, or replace the transformed 

 portions, of similar matters in the human body. It consists, further, 

 in increasing very consideraldy the deposition oi fat — one of the 

 MOW- flesh-forming, but most concentrated of the respiratory and fat- 

 storing constituents of human food. 



It is then in our meat-diet, of recognized good quality, to which 

 is generally attributed such a relatively \i\^Jlesh-forming capacity, 

 that we carefully store up such a large proportion of Jiow-flesh-form- 

 ing, but concentrated respiratory material. 



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 

 tlistinction 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 



