WATERS from ICELAND. Tir 
would have diffolved it quickly with effervefcence. The quan- 
tity of this earthy fediment, from either of thefe neutralized 
waters, was.very fmall. From gr. 10,000 of Rykum water, I 
could only collect a quantity, which, after receiving an obfcure 
. red heat, weighed the twentieth part of a grain; from the fame 
quantity of the Geyzer water, I’ got about 38 or 39 hundredths 
of a grain. : 
In one of my experiments with Rykum water, I got this ar- 
gillaceous earth from it by another procefs, I had a dry ex- 
tract, obtained by evaporating gr. 20,000 of this water,and which 
weighed gr.164. Thirty grains of aquafortis were added to 
it. This aquafortis was made up of equal parts of the ftrongeft 
nitrous acid and water. The extract was digefted with it fix or 
eight hours, and then diftilled water being added, the mixture 
| was filtrated in a {mall filtre, to feparate the clear acid liquor 
from the undiffolved miatter. The filtrated acid liquor was then 
faturated, and a little more than faturated, with a pure aerated 
alkaline falt, and the faturated mixture was heated to a boiling 
heat. It became muddy, and depofited a fmall quantity of fe- 
diment like mucilage, which being collefted by filtration, and 
dried, and heated to.an obfcure red heat, weighed juft one tenth 
part of a grain, and had the qualities above enumerated, which 
fhewed that it was an argillaceous earth. In another experi- 
ment, I digefted an extract of Geyzer water with ftrong vitriolic 
acid, ‘and thus got from it a fimilar earth; but the quantity of 
it was very little greater than that which I had got by fubfi- 
dence from the neutralized and boiled part of the fame water, 
in the experiments above defcribed. 
THE greater part, however, of the earthy matter had not yet 
_ made its appearance; I mean the filiceous earth. It {till re- 
_ mained in a ftate of perfect diffolution in the neutralized and 
boiled mixtures above defcribed, fome part of which had ac- 
tually paffed through filtrating paper ; and I learned, by other 
_ trials, that the whole of thefe neutralized mixtures might have 
been 
