C 901 ] 
This was contained in a linen rag, fo that the urine 
might readily pafs over it; and a perfon, who ufed 
the Carlfbad waters every morning, after having taken 
them, conftantly made water into that funnel ; from 
whence it came to pafs, that on the fixteenth day 
the done was half diffolved, and the remaining part 
was become fo porous and friable, that it almoft fell 
to pieces. No one can fuppofe that the urine of a 
man perfectly in health would have the fame folvent 
property ; left however that fhould happen, our au- 
thor fufpended a piece of a calculus, weighing two 
drams, in the fame manner with the preceeding, and 
made water upon it himfelf many times a day: but 
this piece of calculus, after twelve days, was fo far 
from being leffened, that it had increafed two grains 
in weight. 
Our author, left he fhould be thought to have de- 
pended too much upon one fet of experiments, made 
others. Among feveral calculi, which Dr. Lieber- 
kuhn had communicated to him, there was one ex- 
ceedingly hard. This he cut into four parts, each 
weighing exactly eighty grains. Each of thefe was 
put into a feparate phial. Upon the firft was poured 
frefh oyfter-fhell lime-water : upon the fecond, Carlf- 
bad water : upon the third, the urine of one who 
drank thefe waters : upon the fourth, the urine of one 
perfectly in health, and who only drank for his break- 
fad; fome cups of tea. Thefe phials were placed in 
the fame manner with thofe before -mentioned, and 
their heat kept conflantly the fame. Everyday thefe 
calculi had frefh liquid poured upon them after the 
old was feparated. At the end of twenty days thefe 
Hones were dried and weighed. The fragment in- 
Vol. 49. f Y -fufed 
