330 DR ALISON'S OBSERVATIONS ON 



may be equal ; and that by the use of highly azotised animal food, the animal 

 matter of the urine may be increased, according to Chossat's observations, from 

 9'9 grains in the ounce to 17 ; and the proportion of urea voided may be even in- 

 creased from 237 to 819 ; and, as we learn from the expei-iments of Chossat, that 

 a great part of this increase may take place within a few hours after animal food, 

 rich in azote, is taken, we can have little doubt that a considerable part of that azo- 

 tized food nmst have passed off bj' the kidneys without having been applied to 

 the nutrition of any of the textures. And this appears to be confimied by obser- 

 vations on that disease which arises from a morbid formation of uric acid in the 

 system, because I think two facts may be regarded as nearly ascertained in re- 

 gard to that state, viz., 1. That it depends essentially on imperfect oxidation of 

 the azotised matters contained in the blood, and destined to excretion ;* and, 2. 

 That it is most generally and effectually diminished by a vegetable diet, lessening 

 the quantity of azotised matter taken into the body ; whereas, if all the azotised 

 matter destined to excretion had been the production of absorption in the body it- 

 self, the introduction of much non-azotised matter, with which the oxygen of the 

 air certainly combines in the circulation, would have left less oxygen to unite 

 with that effete azotised matter, and would have determined, therefore, a greater 

 production of the imperfectly oxidised uric acid, as proportioned to the urea.f 

 These facts seem sufficiently to illustrate and justify the common opinion, 

 that the excretions are furnished, in part, by such portions of the ingesta as are 

 either inapplicable to nutrition or redundant ; and which are, therefore, either 



* This is shewn thus — 



60 120 := 60 CO., Carbonic acid. 



t LiEBiG, taking for granted that it is the non-azotised portion of the ingesta only, that is united 

 with oxygen from the air in the course of the circulation, thought the use of vegetable food improper in 

 this state of the body, as absorbing the oxygen, and causing, therefore, imperfect oxidation ot the azo- 

 tised matter absorbed from the textures, and about to form urea and uric acid. But the observa- 

 tions of Magendie and others, shewing that both in health and disease the proportion of uric acid 

 formed is generally less under a vegetable diet than an animal, particularly when taken in connec- 

 tion with the facts stated above as to urea, must be regarded as proving, that the idea of non-azotised 

 food having that exclusive tendency to unite immediately with oxygen in the blood, must be erro- 

 neous. — See Carpenter's Physiology, § 849, 850. 



