490 PHYSIOLOGY AT THE FAKM. 



the oxygen supplied by the blood seizes the carbon which, to 

 the extent of about one -half its weight,, is a constituent of 

 the muscular tissue, so as respects some part of it entirely to 

 disorganise its living character. It is well known, however, 

 that when oxygen and carbon combine, whether slowly or 

 rapidly, the case is one of combustion, and that heat is the 



ances belonging to starvation, as seen after death, are not manifest.* 

 But were non-azotised aliment capable of sustaining muscular 

 movements, of which such as take place within constitute so nearly 

 the whole phenomena of a living body, why should not the state 

 of starvation under such a diet be at least somewhat postponed 1 

 Urea continues to be secreted when nothing but non-azotised ali- 

 ment is taken, and even when no food whatever is used, so that 

 the connection, in a certain measure, between its formation and 

 the disintegration of the azotised issues is indisputable. The very 

 number of such observers as maintain that an increase of muscular 

 exertion is attended with an augmentation of urea in the urine is 

 an important circumstance in the controversy ; nor is it to be for- 

 gotten that the urea formed may be sometimes retained for longer 

 or shorter periods either in the muscles or in the blood ; and 

 further, that even a deficiency of the watery part of the urine 

 gives rise to a longer retention of the urea as well as of other con- 

 stituents of the urine ; again, that many circumstances render it 

 probable that other azotic compounds besides urea are sometimes 

 formed at its expense within the body, and of these that some are 

 not thrown off with the urine ; in short, that variable conditions 

 may prevent the urine from receiving the whole of the nitrogenous 

 compounds resulting from the disintegration of the azotised tissues, 

 and that it may even happen that when rapid supplies of oxygen 

 are afforded, the nitrogen may escape uncombined, as when albu- 

 men out of the body is burnt in pure oxygen gas. Lastly, there 

 is the well-established fact, that dietaries for such animals as the 

 horse and ox, drawn from extensive experience of the admixture 

 of food required by these animals for the maintenance of health 

 and strength, respectively show, under repose and labour, that, in 

 * See 'Lancet,' April 1863. 



