C 8 99 ] 
But this continued only two or three days, and after- 
wards went quite off ; and this nobleman from that 
time was relieved from his former complaints, has 
enjoyed and does yet enjoy the moil perfect health. 
In the year 175-4, our author became poffeffed of 
a calculus, which was of a flinty hardnefs, and bore 
a bright polifh. It weighed a quarter of an ounce. 
He Conjedured, that a much longer time would be 
neceftary to diffolve this hone ; but what was very 
remarkable it diffolved fooner than the reft : for after- 
having been immerfed twenty- four hours, two grains 
of it only remained undiffolved. This done was not 
placed in the china bafon as the others were, but 
fufpended in a little loofe -woven net, that it might 
more freely be wafhed by the water. Dr. Lieber- 
kuhn was at this time at Carlfbad ; he was prefent 
at this experiment, and was witnefs of its truth. 
The net ufed in this experiment was covered with 
a tophaceous cruft, from being fteeped in the 
water. 
The next year, when Dr. Lieberkuhn returned to 
Carlfbad, he brought with him, for experiment- fake, > 
feveral calculi, fome of which were large ones. He 
made there many experiments, in which our author 
affifted. A large ftone was fawed into four pieces 
nearly equal. One of thefe, weighing 99 grains, 
was put into a little linen bag, and immerfed in the 
fource called Brudel : the fecond, in like manner, 
which weighed 96 grains, into that called the New 
Spring: the third, weighing 93 grains, into that 
near the mill : the fourth was fet apart for other 
trials. After four days immerfion they were feverally 
examined. The firft had loft 8c grains ; the fecond,, 
thirty*- 
