[ 27 ] 



However, I acknowledge that the caufe of the flony appear- 

 ance which lavas after cooling exhibit, difcovered by Sir James, 

 appears to me at prefent by far the mod probable ; and that in 

 this refped his difcovery is of great importance to geology. But 

 I perfift in thinking his experiments afford no confirmation of 

 the high degrees of heat attributed to volcanos, and flill lefs to 

 the many hypothefes gratuitoufly heaped on each other by Dodor 

 Hutton, or to the volcanic origin of whins or traps, for the reafons 

 already alfigned. 



D a 



