( 385 ) 



meafure, at leaft, may explain the pheno- 

 mena. 



At the fame time it is to be obferved, 

 that we know not but that in thofe immenfe 

 laboratories of Nature which we call volca- 

 nos, certain gafeous fubftances, hitherto un- 

 known to us, may be produced or developed 

 by the means of fire, and adt a confiderable 

 part in their eruptions and explofions. Of 

 the exiftence and nature of thefe fubftances, 

 perhaps, we may not always remain igno- 

 rant. 



VOL. III. Co CHAP. 



