MINERALOGY. 147 



SECT. CXL, 



2. Volatile alkali, Alcali miner ale volatile. 



This perfectly refembles that fait which 

 is extracted from animals and vegetables, 

 under the name of alcali volatile, or fal 

 urinofum, and is commonly confidered as 

 not belonging to the mineral kingdom ; 

 but fmce it is difcovered not only in molt 

 part of the clays, but likewife in the fubli- 

 mations at Solfatara near Naples, it cannot 

 pofiibly be quite excluded from the mine- 

 ral kingdom. 



Its principal qualities are that, 



a. In the fire it rifes in forma ficcd, and 

 volatilifes in the air, in form of corrofive 

 vapours, which are often five to the eyes 

 and nofe. 



b. It precipitates the folution of the mer- 

 curial fublimate into a white powder. 



r. It alfo precipitates gold out of aqua 

 regia, and detonates with it, becaufe 



d. It has a reaction in regard to the acids* 1 

 though not ib ftrongly as other alcalies. 



e. It tinges the folution of copper blue, 

 and diffolves this metal afreih, if a great 

 quantity is added. 



f It deflagrates with nitre, which proves 

 lit it contains a phlogifton. 

 It is never found pure, but 



SECT. CXLI. 



A. Mixed with 



1. Salts, Alcali miner ale volatile falibus 

 mixtum. 



hi a. With 



