[ x 33 ] 
tion of the milk demonftrates an acidity in the water, 
and the other appearances fhew that acidity to be 
owing to an aluminous fait. 
It appears, that the milk requires a large quantity 
of the water, to make a fenfible coagulation in it: 
for, in the 2 2d experiment, one part of the milk be- 
ing added to four parts of the mineral water, the 
coagulation was fcarcely difcernible : and in the 23d, 
when an equal or larger quantity of milk was added 
to the water, the coagulation was not at all obfervabie. 
I have heard it confidently averred, that this mineral 
water did not at all curdle milk ; which, I fuppofe, 
has been thro’ a miftake in the experiment, in add- 
ding too large a proportion of milk to the water : 
for in this way the coagulation cannot be obferved. 
I imagined, that when the water was boiled with 
milk, the mixture would have become of a muddy 
yellow colour, by the feparation of the ochre : but 
it did not even appear, that the ochre was at all fe- 
parated from the mixture, as it is from the water 
when boiled by itfeif. On the contrary, not only 
the coagulum, but alfo the liquor, was of a pure 
white colour, and of a pleafant tafte : and this 
makes me think it worth the inquiring into, whether 
or not the water does retain its medical qualities after 
it is prepared in this manner with milk ? For, if it 
does, fuch a preparation might certainly be very fer- 
viceable in many cafes. 
Thefe experiments, which we next relate, do not 
only afcertain the exiftence of alum in the water 
J 
with greater certainty, but alfo, that there is a par- 
ticular kind of earth conjoined with this fait. 
