CALORIFICATION. 371 



districts in devastation and ruin. They will 

 more especially take place in those situations 

 of the world, where bituminous and sul- 

 phurous strata and other substances exist, 

 constituting the pabulum with which the mat- 

 ter of light may unite and become igni- 

 ted. In many countries it cannot be other- 

 wise : sulphur is often found to subsist in 

 collected masses in a native form, and the 

 quantity of kali and of wood, furnished by the 

 decomposition of vegetables that have perished 

 and decayed all furnish ingredients for the 

 formation of inflammable powder : a certain 

 degree of heat alone is necessary to ignite such 

 a mass. When we reflect on the quantity of 

 fire and of air which is evolved during the 

 process of fermentation, we shall readily admit 

 the efficiency of the means to produce the end: 

 wherever the strata of the materials I have 

 mentioned, subsist in great abundance, and 

 continue to great extent, I see no impedi- 

 ment to the production of inflammation, mani- 

 festing the phenomena of heat and of color, of 

 expansion the effect of ignition, and the conse- 

 quent explosion of the incumbent parts, un- 

 dermining and springing the foundations of the 

 strongest habitations, and involving them all in 

 one general wreck.* 



* I recollect in my early infancy, that there was a laboring 

 gardener, who used to entertain the little children of the neigh- 

 B B 2 



