MfeTHODS BY WHICH s6DA IS PREPARED. 54"3 



Other manufacturers grind together 500 cwt. of Glauber's Another procefs. 



fait of the bleachers, and 100 cwt. of charcoal; they expofe 5^^^ 



this mixture in a reverberatory furnace refembling a baking decompofed and 



oven, till the matter when ftirred with a rake becomes pally. ex P* lle J ft h ' at 

 , , . , /it Wltn charcoal, 



It is then withdrawn and transferred into large calks; each 



provided with a double bottom. Water is then fuffered to 

 ftand one inch high over it for 24? hours ; the cock is then and the foda ex- 

 opened, the folution runs through the perforated bottom, over £ aaed b ? water » 

 which a ftratum of ftraw had been previoufly placed ; and is 

 thence conducted into the boiler for evaporation and Cry (la l- 

 lization *. 



It is a curious fact, that iron plates are abfolutely neceffary The heat muft 



to conftitute the furface on which thefe articles are expofed to . be a P? licd cn aa 



r iron, and not a 



heat : fire bricks do not anfwer. It feems as if the iron affifted i> r ick hearth. 

 the union j though neither iron filings mixed with the articles 

 nor pyrites are found of advantage* 



This method of making foda is extremely uncertain. If the t/ncertainty of 

 heat be not raifed gradually, or if the mixture be not fufed thjs method * 

 enough, or a little too much, it does not fucceed. Theworft 

 event is, that when the mixture has been made too hot; ful- 

 phuric acid is produced, and fulphate of potafh is formed. 



The quantity of foda which may be obtained by this procefs, it is (aid to be 



is faid to be equal to that obtained by anv other method. profitable if well 



-. . . » -A managed. 



I have been lately informed, that in Germany foda is made Third method. 



by decompofing the fulphate of foda by means of acetite of Sulphate of foda 

 J , • • , - i, • i r ^ / r r , decompofed by 



lime ; the acetic acid is obtained tor that purpole trom wood, acetite of lime,'. 



and the charcoal is found to pay the cofts. of which the 



The method recommended by feveral chemifts, of obtaining dialling w»ZL 



foda by decomposing Glauber's fait by acetite, or the oxide's The method re- 



of lead, does not anfwer in this country. The iriafs is by far aSoftJ? 



too bulky ; and requires too much time, attendance, arid fuel or elfe oxides of 



to reduce it to a narrow compafs. I have been informed by tI J^ u n ^ tal ls f 



men well (killed in this department, that it is nearly impracli- lofs in this 



cable in the large way. The muriate of lead which is pro-^, untr y # 



i j. ? r a LV • . . r The muriate of 



duced cannot be ufed as a white pigment, as the inventors lead thus ©b- 

 pretend. t f ,ned * s not a 



In Pruffia they mix muriate of foda and quick lime together ; pfujfun method 

 then flake the lime, and form the whole into a thick pttfp, D y quicklime; 



then flaking and 



^ «,-, • , /. ,i /. , , .:, ,on S expofure to 



* This was the procefs at the fait works.— N. the air. Product 



R fulphate of lime 



1 Which an d carbonata of 



foda. 



