The Subject Propounded. 9 



fhe pyrites - 9 fometimes with fal ammoniac, where- 

 by I have procured the faffron iron-flowers ; 

 fometimes I examined it by detonation with falt- 

 petre, in order to find out the different propor- 

 tions of its inflammable earth : and laftly, took 

 a great deal of pains in affaying it, by employing, 

 as additions, various forts of earths and flones 



Volcanos and *Iherm<e, are, in a great meafure, 

 owing to the effects produced by the pyrites in the 

 bowels of the earth. As it is well known that iron 

 and fulphur perfectly, and with eafe, take fire along 

 with water. By means of thefe it was, that the 

 elder Lemery attempted, in the fmall way of expe- 

 riment, to imitate the effects of volcanos and earth- 

 quakes. And for this purpofe he ground iron 

 and fulphur, which, with water, he made into 

 a pafte -, which, after (landing for two or 

 three hours in the open air, began, without any 

 application of fire, to grow remarkably warm, 

 then hot, at length to heave and ferment •, and 

 thus the mafs, in feveral places up and down its 

 furface, came to have feveral cracks and rents, 

 thro* which there tranfpired a fume, which proves 

 only warm in fmaller, but actually takes fire in 

 larger maffes, as of thirty or forty pounds. From 

 this experiment he attempted to account for the 

 burnings of Vefuvius, ALtna y Uc. And with that 

 view he proceeded as follows. " I put, fays he, 

 " fome of this mixture of iron and fulphur, both in- 

 " to larger and fmaller, and into taller, narrower 

 " pots •> and the matters, as lying there more 

 fC clofe and confined than in earthen dimes, be- 

 " came more violently heated and heaving, and 

 " in part fprung out of the pot. Further, in 

 " fummer- weather I filled a large pot with fifty 

 " pounds of this matter, and covering the pot 

 *' with a linnen-cloth; buried it about a foot deep 



"in 



