DOMAIN XT. DECOMPOSED. 



destroyed. How the alkaline part of the 

 nitre, which is one of the products result- 

 ing from the decomposition of this stone, 

 is formed, is as yet mysterious ; is it not 

 from the tartarin lately discovered in clays 

 and many stones? I am as yet inclined to 

 think, that it is derived from the putrefac- 

 tion of vegetable and animal substances ; 

 and though nitrous acid formed of oxygen 

 and air, from putrefying substances, be 

 found united not only to the absorbent 

 earths to which it is exposed, but also to a 

 fixed alkali ; yet I should rather suppose 

 that the alkali is conveyed into those earths 

 by the putrid air, than newly formed ; and 

 the reason is, that tartarin, notwithstand- 

 ing its fixity, is also found in soot; and 

 in the same manner may be elevated in 

 putrid exhalations. As to the common 

 salt, said also by Dolomieu to be found in 

 the blisters of this mouldering stone, I am 

 as yet in doubt ; for common salt was also 

 said to accompany the native nitre found in 

 the pulo of Apulia ; yet Klaproth, in ana- 

 lysing this nitrated earth, could find none : 



