in A P y r i t e s. 159 



* of the fulpbur, which almoft always carries along 



* with it the other three principles. 



c In a clofe fire, namely, in fublimation and 



* diftillation, ail the four parts, of the fulpbur af- 

 c cend and pafs over together, without undergo- 

 ' ing the leaft degree of alteration in their mix- 



* tion. 



c In an open fire they are alio diffipated toge- 



* ther, yet, in this operation there happens a fe- 

 c paration of the fatty principle, which feparates 

 4 in the flame, from the faline \ the faline unites 

 c with the moifture of the air, and makes what we 



* czWfpirit of fulphur; by this means fetting itfelf 



* free from all inflammable fattinefs, fo that no 



* remains of it can be obferved. This fpirit of 

 c fulphur is only the acid fait of this mineral, and, 

 4 in every refpecl, refembles that from vitriol.' 



4 'Tis difficult to afcertain the quantity of this 



4 acid fait in common fulphur -, for, the operation 



4 whereby this fait is procured, is commonly per- 



4 formed by the accenfion of the fulphur : now as 



c no accenfion can happen without a free accefs of 



< air, moft of this acid of the fulphur is diffipated 



* and loft ; we, however, fometimes procure more, 

 c fometimes lefs, in proportion both to the fkill 

 ' of the artift, and the quality of the air. I em- 



* ploy a peculiar method for the purpofe, fo as 

 4 from a pound of flowers of fulphur ', to have fome- 



* times an ounce, fometimes an ounce and a half, 



* as follows. 



c I take the largeft glafs receiver I can get, and 



* make a hole therein, between eight and ten 



* inches broad % this glafs I hang, like a bell, quite 



4 clofe 



