356 The Hijlory of 



great variety near Almerode, alfo in the clay and 

 blue marl pits of Munden, and other adjacent 

 places ; yet I know of none undergoing fo fpeedy 

 a change as thofe Almerode pyrites found in the 

 potter's clay : fince I have been aiTured by per- 

 Ions of credit there, that being dug frefh in fum- 

 mer weather, and moiftened a little by means of 

 a warm rain, and afterwards lodged in a fhady 

 place in the open air, they vitriolife in a few 

 days Laft fummer I obferved a phenomenon 

 entirely uncommon, and perhaps peculiar to the 

 minera martis fulphurea, rather than folaris> of 

 Almerode : namely, that having placed a large 

 wooden trough with this mineral, moil of it be- 

 ing already become a vitriolic powder, on a floor 

 four ftory high, which was indeed dry, but iuf- 

 ficiently expofed to the air, fanning though the 

 open windows. In the beginning of the fummer, I 

 unexpectedly obferved this matter to become moid, 

 and gradually ftill fofter, nay laftly, fluid, and begin 

 to trickle through a fmall rent in the trough. 

 Upon which this fluid matter, together with its 

 thick bottom, was put into other vefTels, and by 

 the addition of more water fully elixated. The 

 clear lie being poured off, was put into open, flat 

 glaflfes, and committed to the gradually increasing 

 fummer heat, till become quite dry : by this 

 means I in fome time procured from this liquor 

 a green vitriol, and a yellowifh dry bottom or 

 fadings, eafily pulverable. But in the immedi- 

 ately Succeeding autumn this dry bottom was de- 

 liquated anew, and changed to a fluid matter, not 

 unlike, in colour and tafte, an unrectified oil of 

 vitriol, in which ftate it continues to this day. 

 There moreover appears in the courfe of the 

 crumbling of this pyrites, a circumftance altogether 

 peculiar and very memorable -, namely, that it 



then 



