C lix ] 



mous Grotta del Cane near Naples; 

 It is this air with which fome mine- 

 ral waters are impregnated, and to 

 which they owe their pungent tafte 

 and their virtue, as, for inftance, , 

 Seltzer waters. It is that air which 

 arifes in abundance from calcarious 

 ftones, by the addition of vitriolic 

 acid. This air may be known by 

 the following properties: it extin- 

 guifhes flame ; it is abforbed by wa- 

 ter, and communicates to it the fame 

 pungent, acidulous tafte as Seltzer 

 water has, fo as not to be diftin- 

 guilhed from it either by the tafte 

 or by its virtues; it precipitates 

 quick lime from water; it immedi- 

 ately cryftallizes oleum tart art per 

 deliquiuni) when put in a veffel lined 

 with this oil ; it is mortal to animals 

 breathing in it. 



Evdw- 



