179'^* TDSSILE AlKALI. 35 



Many fruitlefs attempts have been made to feparate the 

 alkali from Glauber's falts, by the intervention of charcoal, and 

 to leave it uncombined with any conliderable portion of ful- 

 phur; therefore, if mine be found in any tolerable degree to 

 anfwer the purpofe, it may perhaps efcape without the feverity 

 of cenfure. If any gentleman wifhes to make trial of this 

 fcherae upon a large fcale, it will afibrd me much pleafure to 

 give him all the afliftance in my power. 



Should any unforefeen difficulty occur on a large fcale, in 

 feparating the fulphur from the alkali, metallic calces may be 

 applied. This you fuggefted to me in your letter, and at the 

 fame time Juftly ohferved, that the " fcales of hammered iron," 

 which are to be found in every fmithy, would anfwer the pur- 

 pofe. 



If this method be followed, the metal muft be ufed in the 

 moift ftage of the procefs, for in the dry way fulphur has a 

 llronger affinity to fixed alkali, than to any other known fub- 

 itance. 



When the hepar has been diflblved, and the folution moftly 

 evaporated, it muft be triturated or beaten with the iron 

 fcales, in order to form an union between the fulphur and the 

 iron„and to leave the alkali difengaged. The remainkig part 

 of the procefs may be carried on according to the former direc- 

 tions. 



I am. Sir, 



with much efteeai, 



your fincere friend, &c. 



J. WILSON. 



