430 DOMAIN XII. VOLCANIC. 



to carry back a freight of this merchandise. I 

 was not, however, actuated merely by those 

 motives of curiosity that might induce any tra- 

 veller to visit this remarkable mountain ; I pro- 

 posed to examine it with the eye of a philoso- 

 pher and a naturalist. 



Origin. " The pumice-stone, with respect to its origin, 

 though universally admitted to be the product of 

 fire, is one of those bodies which have divided 

 the opinions of the chemists and naturalists both 

 ancient and modern. It may, in fact, be af- 

 firmed that it has given rise to as many hypo- 

 theses and extravagant suppositions, as the 

 question formerly so much agitated relative to 

 the nature of the yellow and grey amber. With- 

 out noticing the more absurd of these, I shall 

 only mention that Pott, Bergman, and Demeste 

 imagined that pumices were amianthuses decom- 

 posed by fire; Wallerius, that they were coal 

 or schistus calcined ; Sage, that they were sco- 

 rified marls ; and lastly, the Commendator Do- 

 lomieu, that they were granites rendered tume- 

 fied and fibrous by the action of the fire and 

 aeriform substances. 



" The most effectual method to investigate the 

 truth in so obscure a question, appeared to me 

 to make the most accurate and minute observa- 

 tions on the spot; to collect and attentively 



