exiraBlng Marine Salt from Sea Water, 



119 



fo-rnied by a combination of an abforbent earth, or magnefia 



and thevitriolic acid. It is by the decompofition of Epfom fait, 

 or difunion of thefe conftltuent parts, that we obtain genuine 



mao-nelia 



There 



diverfity in the minutia of the procefs 

 even in the hands of chymical operators ; butiince Mr. Henry, 

 of Manchefler, (England) has improved upon the procefs 

 and his magnefia having juflly obtained celebrity and prefer- 

 ence on account of its delicate whitenefs and purity, Iiis meth- 

 od jChould be recommended as mod eligible for our imitation. 

 The following isnot effentially varient from Mr. Henry's procefs. 

 " Take any quantity of Epfom fait, diffolve it in boiling water, 



_ % 



Ifo half the quantity of good 



and filter the folution. DilTol 



pearl 

 ought 



llv and filter the folution. Both of tKefe foluti 



s 



be fomewhat diluted, and 



the quantity of 



hich 



falts 



t will be proper to ufe 

 ould fairly dilTolve the 



Mix the two folutions when nearly cold, and flir tl 



very well togeth 



Let the mixture ftand for fome 



until the precipitate has fall 



the bottom in form of 



coarfe gritty powder. Put the whole then into a clean copper 

 kettle, under which a moderate fire is made. Stir the matter 



ffantly \vith a large wooden fpatula, to prevent the po^- 



de 



from fticking to the bottom. ~^s the mi 



heats, the 



powder begins to loofe its fandy appearance, and to increafe 



greatly in quantity ; {o 



though at firfl the mixture was 



quite thin, with only a fmall portion of fandy matter amongd 

 it, before it has attained the boiling heat, it will be fo thick 



that it can fcarcely be fllrred. 



\^^hcn the grittinefs is 



quite 



gone 



