CG THE CHEMISTRY OF THE FARM. 



buminoids of the animal frame, but also the gelatinoids, 

 the hair, wool, horn, &c., and to some extent the fat. 

 By the combustion of albuminoids in the body heat and 

 mechanical force will also be developed. Albuminoids 

 thus supply in themselves most of the requirements of the 

 animal — a statement which can be made of no other food 

 constituent. The albuminoids of food are frequently 

 described in analyses as " flesh-formers." 



An animal, even when not increasing in weight, will 

 always require a certain constant supply of albuminoid in 

 its food to replace the waste of nitrogenous tissue which 

 is always going on ; the amount thus required is but 

 small, in the case of an adult man at rest it amounts to 

 about fifty grams (IJ oz.) per day. 



When the nitrogenous tissues, or the albuminoids con- 

 sumed as food, are oxidised in the body, the nitrogen 

 they contain is not burnt, but excreted in the form of 

 urea. The urea produced is one-third the weight of the 

 albumin oxidised. When the albuminoids, either of the 

 food or of the wasting tissues, are only partially oxidised, 

 fat as well as urea may be produced. Theoretically, 

 100 parts of albumin may yield 51*4 parts of fat. 



When amides are consumed as food they are burnt in 

 the system, and their nitrogen excreted as urea. Amides 

 cannot supply the place of albuminoids as muscle-formers, 

 but by combustion they serve for the production of heat 

 and force. 



The fatty matter contained in food is similar to that 

 found in the animal body, but an animal is apparently 

 capable of transforming one kind of fat into another. The 

 fat of the food is either burnt in the animal system to 

 furnish heat and mechanical energy, or it is stored up as 



