324 MAGNKSIAN EARTH* 



i^ n th th tlr e'wf ^no'her method may be followed in places where fulphurets 



where pyrites are are worked ; or where, as at Brozo, there is a manufacture of 



burned. fulphate of iron. The kiln, where the pyrites are burned, may 



be wvereYwkh ^ e coverecl ^Hh an heap of the magnefian earth ; the fulphu- 



a heap of mag- ric acid, which is difengaged will be abforbed by the magne- 



nerian cart . fa . am j iQ ^ ac jvantage of putting an end to the complaints 



of the owners of property near the manufacture, will be added 



Which- when that of julphatin<r the magnefia, from which the fait may after- 



(ulphated by the . / .!,*•- ™ • , „ r ■<•■ 



acid vapours, wards be procured by hxiviation. This laft procels, it it were 



may be lixivi- introduced into the manufactory of Brozo, would produce the 



ac * fulphate of magnefia of commerce at a very moderate price. 



The magnefian As the magneiian earth of BaudilTero forms an excellent 



Tt«la-mand f ° r P orceIain vvith flIex ' ' li prefents befides an interefting fubject 



pottery, for refearch relative to the fabrication of pottery. With this 



earth and a quantity of the argillaceous earth of Caftellamonte 



and mixed with fufficient to unite it into a pafte, I formed fome crucibles and 



c^^remd" ca P fuIes - Thefe crucibles were expofed for 48 hours in the 



hard. furnace of the g'afs-houfe of Po. The earths did not feem to 



have formed a fufficient union; neverthelefs the hardnefs of 



- the crucibles was fuch that they could not be affected by the 



file. Doflor Gioanetti, who is now engaged in manufacture 



of ftone-ware pottery, will hereafter throw light on this fub- 



jeft. 



I end this part of my memoir vvith obferving that the trials 

 which I made of this earth as an abforbent in veterinary medi- 

 cine fucceeded perfectly well. 



Additions to the preceding Memoir, by the fame . 



The earth of Farther researches which I made on argillaceous earths have 



Caftellamontc Is ' given me to underftand that the earth of Baudiflero is not the 

 fcmilar to that of b , 



Baudiflero. only one known that conn Its for the molt part or magnefia. 



. The fame kind is alfo found at Cailellamonle, a large village 

 near that of Baudiffero. 



M. Bertoline, doctor of medicine, one of the molt eminent 

 of my pupils, having repeated the detail of the experiments 

 m which we made at the general fchool of chemiftry, invited us 

 to eflay a particular earth of Caftellamonte, his country, which 

 he thought would furnifn the alumen which was fought for un- 

 (uccefsfully in the earth of Baudilfero ; foon after, by the care 

 of M. Onorato, furgeon of Caftellamonte, who is the pro- 

 prietor 



