from the Lipari Islands. 537 



Nos. 40. to 45. are specimens of the different rocks found 

 in the same situation. Some of them evidently decomposed, 

 and much changed, by the action of heat and acidulous fumes. 



Nos. 46. and 47. are specimens of the native sulphur, as it is 

 collected and conveyed to the manufactory. The former is some- 

 what crystallized ; while the latter presents a fibrous structure, 

 and was taken in a hot state from the mouth of a fumarole. The 

 minute white silky crystals occupying the interstices in the slaggy 

 mass of No. 48. seem to be selenite. 



No. 49. is the native alum from this island, disposed in veins 

 of a fibrous structure, and having a shining silky appearance ; and 

 No. 50, is the beautiful white boracic acid, which forms in sub- 

 limation on the surface of the sulphur, to the depth of from half 

 an inch to two inches ; and of which variety the crater of Vulcano 

 is the principal locality. 



