NEVr SPECIES OF URINARY CALCULUS. 22/ 



theless one suggestion, with respect to the prevention of , 

 calculous complaints, so nearly connected with my present 

 subject, that I think it may deserve to be recorded. 



Since the white matter contained ii the urine of birds, Uric acid In 

 which is voided along with their dung, has been remarked J'^Y^i'^g^i 

 by Mr. Vauquelin, to consist principally of uric acid, I have 

 paid some attention to the different proportion in which 

 this matter is voided by different species of birds, to see 

 how far it accorded with the different qualities of their food. 

 And I found, that in the dung of the goose, feeding wholly seems pro- 

 oa grass, the proportion did not seem so much as -j-J^^ ^i* portional to 

 the whole dung. In that of a pheasant kept in a cage, and of animal food 

 fed on barley alone, it was about y^ part. In that of a ^^^' ^*^^> 

 hen, having the range of a garden and farm yard, and 

 consequently procuring insects, and possibly other animal 

 food, the proportion was manifestly much greater, and com- 

 bined with lime. In the dung of a hawk, fed upon flesh 

 alone, the quantity of matter voided in a solid state bears 

 but a small proportion to the residuum of uric acid, that is 

 left by the urine when dry. And in the gannet, feeding particularly of 

 solely on fish, I have observed the evacuations in some in- fisii. 

 stances to be mere urine, for it contained no solid matter 

 excepting the uric acid. 



It seems, consequently, deserving of inquiry, what changes Hence calca- 



might be produced in the urine of any one animal, by such lousandgoutr 

 ,.,. J. . ..*^ persons should 



alterations ot diet, as its constitution would permit; for as prefer a ve^e- 



far as any inference can be drawn from these varieties, which ^*^^^® ^•^^^• 



naturally occur, it would appear, that persons subject to 



calculi, consisting of uric acid, as well as gouty persons, in 



whom there is a redundance of the same matter, have much 



reason to prefer vegetable diet: but that the preference 



usually given to fish above other kindi of animal food u 



probably erroneous. 



Q « IX. 



