Manufacture of Potash. 95 



be sifted ; the larger parts, or charcoal, should be returned to 

 the fire, and burned to ashes. These, as soon as the sifting 

 is completed, must be stowed away under cover, until it is 

 desirable to commence the lixiviation. 



For this a certain number of casks must be prepared, by 

 having a false bottom placed at a few inches above the 

 real bottom. The false bottom may either be formed of a 

 plank perforated with holes, or an open framework : in 

 either case it must be covered, either with a double thickness 

 of blanket, or five or six inches of clean straw. A cock 

 should be inserted below the false bottom in each cask. These 

 casks will be ranged alongside of each other, and a gutter 

 placed under the cocks, so that the liquor, after 

 having been filtered in these casks, may pass ofi" to a 

 reservoir, from which it will either be pumped or ladled into 

 the boilers for evaporation, or returned to the same, or a 

 fresh set of casks, to be more strongly impregnated with 

 the soluble salts of the ashes. The casks being thus 

 arranged, a quantity of ashes is placed in each, and an 

 equivalent bulk of water is poured in ; the quantity 

 of ash being so regulated as to nearly fill the cask 

 when the water has been poured upon it. The water 

 is allowed to remain undisturbed for about 24 hours, when 

 the cocks are opened, and the whole is discharged into the 

 reservoir. Another charge of water is then poured upon the 

 ash ; and this, after being allowed to remain in contact 

 with the ash for about three or four hours, is drawn off into 

 the same reservoir. In some instances it may be as well to 

 commence at once to evaporate these two solutions, in order 

 to clear the reservoir for the reception of the liquor of two 

 more washings of the same ash ; but in others it may be as 

 well to have a second reservoir for the water of the two last 

 washings, which will never be rich enough in potash to make 

 it worth while to evaporate it. After having been thus 



