FOOD. 65 



of various nutritive substances together, often highly increase the 

 exquisiteness of taste and flavour, the culinary art is cultivated 

 not only for health, but also for luxury. 



The chief proximate principles of animal food are fibrin, 

 albumen, gelatine, oil, and sugar ; of vegetable, gluten, fecula, 

 mucilage, oil, and sugar. My not less excellent than distinguished 

 friend, Dr. Prout, in the paper which was honoured with the Cop- 

 ley medal of the Royal Society , reduces all the articles of 

 nourishment among the higher animals to three classes: the sac- 

 charine, oily, and albuminous. The first comprehends sugars, 

 starches, gums, acetic acid, and some other analogous principles; 

 the second, oils and fats, alcohol, &c. ; the third, fibrin, gelatine, 

 albumen, and caseum or the curd of milk, with vegetable gluten, 

 so abundant in wheat. He has favoured me with the following 

 remarks, which are chiefly an abstract from a work on digestion, 

 commenced by him in 1823, but not yet published. 



" Observing that milk, the only article actually furnished and 

 intended by nature as food, was essentially composed of three 

 ingredients, viz. saccharine, oily, and curdy or albuminous 

 matter, I was by degrees led to the conclusion that all the 

 alimentary matters employed by man and the more perfect ani- 

 mals might, in fact, be reduced to the same three general heads ; 

 hence I determined to submit them to a rigorous examination in 

 the first place, and ascertain, if possible, their general relations 

 and analogies. An account of the first of these classes, viz. 

 the saccharine matters, has been published in the Philosophical 

 Transactions, and the others are in progress. The characteristic 

 property of saccharine bodies is, that they are composed simply of 

 carbon united to oxygen and hydrogen in the proportions in which 

 they form water; the proportions of carbon varying in different 

 instances from about 30 to 50 per cent. The other two families 

 consist of compound bases (of which carbon constitutes the chief 

 element) likewise mixed with and modified by water, and the pro- 

 portion of carbon in oily bodies, which stand at the extreme of the 

 scale in this respect, varies from about 60 to 80 per cent.; hence, 

 considering carbon as indicating the degree of nutrition, which, 

 in some respects, may be fairly done, the oils may be regarded 

 in general as the most nutritious class of bodies; and the general 

 conclusion from the whole is, that substances naturally containing 



Phil. Trans. 1827. 

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