116 4n ANALYSIS of 
Experiments to learn the quantity of the neutral falts. 
Tue only ingredients of thefe waters, the quantity of which 
had not yet been examined, were the neutral falts. The preli- 
minary experiments, and the appearances obferved in the wa- 
tery folutions of the extracts of thefe waters, gave me reafon 
to be fatisfied, that thefe neutral falts were partly common {alt - 
~ and partly Glauber’s falt. To afcertain the quantities of them, 
I made the following experiments: I had fome common falt, 
which had been refined by a fecond cryftalization, and was in - 
folid dry and large cryftals. Of this I weighed ten grains ex- 
aétly, which were diffolved in about half a pound of diftilled 
water. I then added a folution of filver, which contained a 
little fuperfluous acid. The filver was precipitated in the form 
of luna cornea or argentum muriatum ; and I took care to add 
rather more than the quantity which the ten grains of common 
falt could precipitate. The lina cornea, after complete fubfi- 
dence, and decantation of the faline water from it, was care- 
fully collected on a fmall filtre, and well wafhed with diftilled 
water, and thoroughly dried and weighed. I thus learned, that 
100 parts of common falt are fufficient to give 235 of luna 
cornea. This enabled me to learn, by fimilar experiments, how 
much common falt is contained in the Iceland waters, and I 
found that the quantity contained in 10,000 grains of Rykum water 
was gr. 2.90, and in the fame quantity of the Geyzer water, I 
found there was gr. 2.46 of common falt. Some of my readers 
may perhaps be inclined to fufpect, that the Glauber’s falt - 
contained in the Iceland waters, might, by means of its vitriolic: 
acid, cotribute to the precipitation of a part of the filver ; but 
experiments have fatisfied me, that a {mall quantity of vitriolic — 
acid, or of any vitriolic falt, diffolved in a large quantity of 
water, 
