214 PROCESS FOR OBTAINING THE AGUSTINE EARTH. 



X. 



Letter fmm Mr. Ac cum, in anficer to tlie Enquiries of a Cor- 

 refpondciit reJpeSlhig the Procefs for obtaining the Jgiijline 

 Earth. 



To Mr. NICHOLSON, 



DEAR SIR, 



Miftake refpeft- JL OUR correfpondent, P. O. in the laft number of your 



tkfn'of th^ "^^' Jo'^f"^'' 'S corred, when he obferves, that the procefs for 



method of ob- obtaining agufilne earth is not noliced in my fyftem of prac- 



taining agus- jj^j^j chemiRrv, nor in any other work publirtied in this coun- 

 tine earth. -^ ^ '^ 



try, and alfo that moft: of the books he quotes, were pub- 



lifhed a conliderable time after this earth was made knov.n 



by profeflTorTromsdorf; but he is mi (taken in his opinion, that 



it was known in this counlry previous to the publication of 



the above works. 



rirft account. The method of feparating this earth from the mineral which 



contains it, had not then been communicated to us through 



- the ufual channels of fcienlific information. The firft account 



of the method of feparating this earth I can find, is contained 



in agerman work, entitled PraBifche Anleitung zur zerlegenden 



Chiemie, publiQied by Profedor Goetling, 1S02. From which 



the following tranflation is made. 



The prccefs. Let a determinate quantity of the Saxon beril finely levi- 



pounded- boikd g^^^*^' ^^ boiled in a filver vellel, with three or four times its 



■wichpotafhj weight of potafli, diffolved in a fufficient quantity of water; 



''""'■' evaporate the whole to drynefs, and fufe the ma(s. 

 fofcened by Soften the alcaline mafs by the gradual addition of water, 



in muriatic acid • ^"^^ when detached from the crucible, add to it muriatic acid 

 evaporated to till the whole is ditfolved. Evaporate the folution to drynefs, 

 ■wUh^wa'ter'-"and^"'' ^^^ ^^^^ '" *^ fufficient quantity of water, and feparate 

 thefiLxfepa- the infoluble refidue [filex] by the filtre. 



!f^^l' -J Decompofe the fluid from which the filiceous earth has been 



the fluid pre- ' 



cipitated by car- feparated, by gradually mingling it with a folution of car- 

 bonate of foda j bonate of foda ; coUeft the precipitate, and wafh it re- 

 peatedly. 

 feparate the When the precipitate obtained in the laft procefs has 



a umine trom j^^quired fome coi.fiftence, transfer it into a flafk containing 



the precipitate » ' & 



by potafh which a Concentrated folution of polafli. The aluraine which was 

 difibives it 2nd prefent 



leaves thi^ 

 thie cartb* 



agui^ 



