102 



precipitated from the urine of persons in health 

 as long* as it contains free acid, and the want of 

 acid has, perhaps, some share in the precipita- 

 tion, which the sublimate produces in the urine 

 of persons in a feverish state. Besides these ani-, 

 mal matters, the properties of which my prede- 

 cessors had failed to discover, I also found a 

 mineral substance, which had been overlooked 

 by them, viz. silica. This earth is met with 

 in urine, and probably in all the fluids of 

 the body, though in very small quantities, and 

 has been introduced with the water, which we 

 use partly in the preparation of our food, and 

 partly as a daily beverage, and since no processes 

 occur in the body, capable of separating it, it 

 must accompany the fluids until it be evacuated 

 ty the excretions. 



The diseased alteration in the urine, which ge- 

 nerates saccharine matter instead of urea, and 

 which was so fully examined by CRUIKSHANK, 

 has since been still further investigated by NICO- 

 LAS, SORG, THENARD, BOSTOCK, &c. Then- 

 analyses vary as to the results, and show, that this 

 diseased state is not always of the same nature; 

 but they all agree, that the new-formed sugar is 

 very easily destroyed during the experiments! 



