c/'/^ Pyrites; 89 



principally, thefe ftones to prove as cryftalline and 

 tranfparent as the clear tacks or fpikes on drufe ; as 

 appears from the following experiment. Take the 

 freih urine of a boy, leave it to ftand for three or four 

 years in a ftaunch, large cucurbit, about half full, 

 covered over with a bladder, on a fhelf, in a room of 

 fo temperate a warmth, that fcarce any thing fhall 

 evaporate (tho 9 it be impofTible but fome mould) 

 but only amidft tender mounting fleams, trick- 

 ling down again in drops, the leaft diftinguifh- 

 able feparation, that can be procured. Now, af- 

 ter hitting on the proportion of the veflel, and the 

 due degree of warmth, there will accordingly be 

 obferved, fooner or later, after the precipitation 

 of the very grofs, tartareous, earthy particles from 

 this water, above on the rim of the glafs, fmall, 

 white, oblong (tones, of the length and fize of 

 oat-grits, adhering fo firmly to the glafs, as to 

 remain undifturbed upon decanting off the urine. 

 The firft time I came to obferve them, I could 

 have averred them to be a cryftallized fait; but, 

 upon rinfing them carefully out, they evinced no- 

 thing laline on the tongue -, nor, according to the 

 known quality of fait, did they admit a folution 

 in the hotted water, fo that they muft be pure 

 cryftalline pebbles, oblong and prifmatical, like 

 nitre-, figures that the quartzy tacks on drufe exhibit 

 moftly, and of which I procured a drachm from 

 fix lb. of urine. This ftoney matter, which may 

 properly be deemed Becker's firft earth, appears 

 alfo in the actual fait of urine, when melted to a 

 glafs. And here we fee how excellently, and how 

 tar, long digeftion, nay, even only time and pa- 

 tience, avail in producing forms and effects, ge- 

 nerally deemed impoflible, and feldom looked for 

 in elaboratories, except in thofe of nature ; whence 

 fuch ftoney matter fhould be generated in human 

 bodies, is not difficult to; be accounted for, 



when 



