( 346 ) ^ 



beginning of the procefs, was carbonic acid 

 gas, and the remainder in purity 1.72 ; 

 and extinguifhed a candle. He remarked 

 that the interftices of this lava contained a 

 fand, which he was not able to feparate 

 from it. 



5^ ounces of lava of Vefuvius gave 30 

 nieafures of air ; the firfl portion of which 

 fliowed a flight appearance of carbonic acid 

 gas ; and the remainder was azotic gas from 

 the degree 1.64 to 1.38, with refped; to 

 what came laft. The retort broke by the 

 inflation of the refldue, when it became 

 cold. 



Another ounce of lava, of the confifl:- 

 ence of a hard fl:one, gave only 2^ mea- 

 fures of gas, principally hydrogenous, de- 

 rived, as he conjed:ured, from the gun-bar- 

 rel in which this experiment was made. 



From thefe refults the Englifli naturallft 

 infers, that it is probable that the true lavas 

 do not afford much air ; which, however, 



according; 



