$6 An 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 mod 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 nowfubmit 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 co.nfidered, 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 

 often 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 muft alfo confefs, that 1 took pleafure in promoting, as 

 far as I could, the information concerning Iceland, which the 

 philofophical zeal and fpirit of the Gentlemen I mentioned, 

 have procured for us. ■* 



Both thefe waters had a weak {mell of the Hepatic Gas, or 

 a fmall 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 fmall, that I 

 was not able, by any experiments, to obtain it in a feparate 

 ftate, or bring it into view in any form whatever. I therefore 

 could not make any attempt to eftimate the quantity of it. 



Those who are acquainted with fulphureous waters, know 

 that an incredibly fmall 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 it is fmall. There was alfo reafon to believe, that 

 fome part of it had already been loft or changed during the 



voyage> 



