{ 3^7 ) 



was certain that the fluids I found in the 

 veflels could not have entered them from 

 without. To the neck of the matrafies I 

 luted a glafs tube, the other extremity of 

 which was inferted in the mercury ; in 

 order that, if any liquor (hould be feparated 

 from the volcanic matters, I might collecSt it. 

 Such a liquor was, in fadt, feparated ; and 

 I found it to be of a nature which I never 

 could have imagined. I fliall defcribe it in 

 a diftind: chapter, to prevent the confound- 

 ing of obje(5ts totally unlike in one difcuf- 

 fion. 



The firft produd on which I made my 

 experiments, was the fixth fpecies of the 

 glaffes of Lipari ; that which I have de- 

 fcribed as having a black ground fpot- 

 ted v/ith white points *. I placed twelve 

 ounces of it in a matrafs, reducing it firft to 

 powder, as I did all thefe produds, before 

 I began my experiments, to deftroy the 

 bubbles that might have been produced by 



* See Chap. XV. 



y 4 the 



