t 5t 3 



C Bitter purging fait, or magnefia, glauber's fait, 

 or Epforn fait, vitriolic acid and magnefia alba. 



HI. INFLAMMABLES. 



These are not malleable or ductile; foluble 

 in oils, but not in water, and readily take fire. 



A. Sulphur, formed of the vitriolic acid, 

 united v/ith the principle of inflammability, is 

 found in all ores, except thofe of tin, bifmuth, 

 and cobalt. It is plentiful in ftrata of coal, and 

 is alv/ays difcoverable from the fmell it emits. 



a. Mundic, or iron pyrites, is fulphur mineralized 

 with iron, and ftrikes fire with Heel, 



b. Marcafite, or copperas, ftony fulphur com- 

 bined with copper, iron, &c, ftrikes firq with 

 fteel. 



c. United with earths, clays, and ftones, fomer 

 times in regular cryftallifed figures ; or in round 

 or fquare mafifes. 



B. Bitumens are either fluid or folid. Liquid 

 bitumen iffues out from crevices in mines, and 

 takes fire by a candle. 



a. Naphtha is a bituminous fluid, found floats 

 ing on the furface of fome waters, particularly 

 in Perfia, from whence it is chiefly procured. 



b. Petroleum, rock or foflil oil, is thicker 

 than the former, ouzes out of the crevices of 

 rocks, whence it receives its name, 



c. Pix judaica, or afphaltum, is of the fame 

 nature, but hard. 



d. Amber, and ambergris, are formed of the 

 principle of inflammability with the muriatic 

 acid. The former is found principally in PruA 

 fia. Ambergris is met wir,h in the greateft 



E 2 quantities 



