[ 29 ] 
perfectly white, hard, and fmooth, and appear to 
confift of a great number of lamellae formed round 
a fmall nucleus. This fort of incruftation has been 
found in no other place ; but there are fome of a. 
browner fort; and more irregular lhapes, which are 
taken out of the Brudel. 
The medicinal virtues of thefe waters have been 
been treated of by German authors. They are 
efteemed to be particularly efficacious in removing 
obftrudtions, and in cafes of the done and gravel j 
of which the treatife lately produced to the Society 
contains many remarkable proofs. They are much 
frequented in thefe and in other cafes ; fo that they, 
have generally 200 perfons in a feafon drinking the 
waters. The feafon begins in May, and ends in 
Auguft. They drink them in the following me- 
thod, They begin with a purge ; and affift its 
operation with ten or twelve chocolate-cups of the 
water taken within five minutes of each other. The 
day following they take the waters in the fame quan- 
tity, and at the fame intervals, keeping themfelves all 
the time in a warm room ; which, with the warmth 
of the waters, occafions a moll plentiful perfpiration. 
This is repeated for feven or eight days, increaiing 
daily two or three cups of the water, till they come 
to drink 25 or 30 cups a day. The operation con- 
tinues from eight of the clock in the morning till 
noon. Some bleed once in the middle of the courfe, 
others not at all. After they have finished this courfe 
of drinking, they bathe two days fucceffively, con- 
tinuing in the bath half an hour, or longer, as their 
ftrength permits them, or their cafe requires. This 
is the whole courfe $ which is repeated two or three 
times. 
