VALUE OF DIFFERENT MATERIALS OF FOOD. 249 



there is an economy in the use of gelatine, in the -form of soup, which 

 diminishes the demand for other azotized matter. The use of animal flesh, 

 however, as a principal article of diet, except when the individual is lead- 

 ing the incessantly-active life of a carnivorous animal, is very far from 

 being economical, and is positively injurious to the welfare of the body. 

 484. On the other hand, in rice, potatoes, cassava-meal, and similar 

 substances, the farinaceous or saccharine components form so very large 

 a proportion of the whole mass, and the proteine-compounds are present in 

 so very small an amount, that they are insufficient to support the bodily 

 vigour when taken alone, unless a larger quantity be ingested, so as to 

 supply the requisite proportion of azotized matter. But when these 

 substances form part of a mixed diet, the other ingredients of which 

 consists of animal flesh, a much smaller quantity of them suffices ; and 

 the same kind of combination is then formed, as exists in the single 

 article of bread. Those in whose diet the farinaceous elements predo- 

 minate largely, and the azotized compounds exist in the smallest amount 

 compatible with the maintenance of the bodily vigour, are exempt from 

 many diseases incident to those who live more highly ; thus among the 

 potato-eating Irish, and the oatmeal-feeding Scotch, gout is a disease 

 never heard of; whilst among the richer classes of the same countries, 

 there is no peculiar exemption from it. 



435. The oily constituents of food are most abundant in the diet of 

 the inhabitants of frigid zones, who feed upon whales, seals, and other 

 animals loaded with fat, and who devour this fat with avidity, as if in- 

 stinctively guided to its use. It is by the enormous quantity of this 

 substance taken in by them, that they are enabled to pass a large part 

 of the year in a temperature below that of our coldest winter, spending 

 a great portion of their time in the open air ; as well as to sustain the 

 extreme of cold, to which they are occasionally subjected. And in con- 

 sequence of its being more slowly introduced into the system than most 

 other substances, a larger quantity may be taken in at one time, with- 

 out palling the appetite ; whilst its bland and non-irritating character 

 favours its being retained until it is all absorbed. In this manner, the 

 Esquimaux and Greenlanders are enabled to take in 20 or 30 pounds of 

 blubber at a meal ; and, when thus supplied, to pass several day without 

 food. On the other hand, among the inhabitants of warm climates there is 

 comparatively little disposition to the use of oily matter as food ; and the 

 quantity of it contained in most articles of their diet is comparatively small. 



436. In the Milk, which is the sole nutriment of young Mammalia, 

 during the period immediately succeeding their bir'th, we find an admix- 

 ture of albuminous, saccharine, and oleaginous substances; which in- 

 dicates the intention of the Creator, that all these should be employed 

 as components of the ordinary diet. The Caseine or cheesy matter is a 

 proteine-compound ; the Butyrine of butter is but a slight modification 

 of its ordinary fats ; and its Sugar differs from that in common use, only 

 by its larger proportion of water. The relative amount of these ingre- 

 dients in the milk of different animals is subject, as we shall hereafter 

 see, to considerable variation ; but they constantly exist, at least in the 

 milk of the Herbivorous Mammalia, and of those which, like Man, sub- 

 sist upon a mixed diet. But it has been recently asserted, that the milk 



