96 4n ANALYSIS of 
brought from thence, and from the Faro Iflands, a number of 
fine fpecimens of volcanic and other foffil productions, and 
along with them, a quantity of the water of the two moft re- 
markable boiling and exploding fprings of Iceland, called by 
the natives Geyzer and Rykum; and having favoured me with a 
portion of thefe waters, and expreffed his defire that I would 
examine them, I have accordingly made a number of experi- 
ments with them, an account of which I fhall now.fubmit to 
the Society. If the detail of it fhould appear tedious ; if I 
fhall be thought to have given much attention to very fmall 
matters ; it muft be confidered, that the nature of the fubject 
’ requires exactnefs. The quantities of the materials which are 
to be examined in fuch experiments, are but fmall, though it 
ofteri happens, that thefe fmall quantities of matter, acting in 
nature for a great length of time, produce accumulations, and 
other effects, that appear very furprifing and worthy of atten- 
tion. I mutt alfo confefs, that | took pleafure in promoting, as 
far as I could, the information concerning [celand, which the 
philofophical zeal and fpirit of the Gentlemen I mentioned,, 
have procured for us. s 4 
Boru thefe waters had a weak f{mell of the Hepatic Gas, or 
a {mall degree of the odour, which is well known in Harrow- 
gate, and other fulphureous waters. The quantity, however, 
of this fulphureous matter in them was fo very {mall, that I 
was not able, by any experiments, to obtain it in a feparate: 
f{tate, or bring it into view in any form whatever. I therefore 
could not make any attempt to eftimate the quantity of it. 
TuoseE who are acquainted with fulphureous waters, know 
that an incredibly {mall quantity of their volatile fulphureous 
matter is fufficient to give a perceptible odour; and it is fo liable 
to be decompounded and changed, while we attempt to feparate 
it from water, that fuch an attempt never fucceeds when the 
quantity of itis fmall. There was alfo reafon to believe, that 
fome part of it had already been loft or changed during the 
voyage,, 
