CAI^CUJLU ^ 345 



t It now only .remained, ta dcmoastpate the identity of Experiments 

 these vavions fu'ecipitates^ with the. aatur.ally (deposited inat- ^jQ^g p^^ gj^jj^^ 

 ter of gravel. For, though it conldriiat be well mis^;*ken, &c. 

 for any other saline composition, iniiyina;. yet, as external 

 characters are, even in the-, hands qf . a, flome : de J^isle,; c^. 

 an Abbe Haiiy, fallacious, the rf oil a%v:in|y-..3©a,' ajn,€^i4*?g' 

 pne, on the subject of acids, was institated. x .'. j t4;.C'cv 



Ejp. 15- To two drachms of this artificial gray ejly mat- 

 ter, was gradually added one auacevof nitopous acid; which 

 acted on it, with elfervescenee, und dissolved the whole*, 

 with the exception of some small, fioatingj. iioculent, animal 

 particles, so well described by. Bergman. 



The evaporated solutiou reddened the skin, and, after 

 sometime, deposited crystals of oxalic acid: as happens in 

 a]l concentrated nitrous solutions, of calculi, yf the uric 

 acid kind. To another small quantity, was added some 

 pure alkaline Jixivium; which very soon took it up, became 

 coloured, sweetish, and deposited the usual silky crystalline 

 sediment, upon the addition of acetous acid. No doubt, 

 therefore, could remain, as to its identity, Avith that natu- 

 rally deposited 



And here, though irrelevant to my present object, and 

 merely with a view to excite the attention of the faculty, 

 may I be permitted to ask, how it happens, that, in the 

 very Avcist kinds of typhus fever, there is very little dimi- 

 nution of the secretion, or excretion of the acidulous phos- 

 phat of lime? as appears by the acidity of the urine, lime- 

 water, and the quant um of precipitate, aftorded by the ox- 

 alic acid : whilst a xery considerable one of the uric acid 

 takes place, and continues so, until nearly the termination 

 of the disease, when it begins gradually again to manifest 

 itself; first, by the usual tests only; but presently, upon 

 the crisis taking place, in such quantity, as to become in- 

 soluble; and, therefore, quickly precipitates, (with some 

 additional mixture of calcareous pho.sphat, and animal mu- 

 cilaginous matter,) under the form of our critical sediment 

 or deposit? Or, are we not here, again, to admire the wise 

 economy of the Author of nature, v.'hich, by keeping up 

 the considerable and necessary bony excretion of the system, 

 prevejats the dany^Tuivs acciiniularion of it, which m'.i.?t en- 



Stt», 



