106 



MANUFACTURE OF SUGAR. 



only the sugar, and soluble salts of potash and soda. If 

 any excess of acid appear after the addition of tannin, it 

 must again be accurately neutralized by lime, and the 

 liquid brought to ebullition. It must then be immediately 

 passed through calico filters, and conveyed to the evapora- 

 tors as rapidly as possible, when the more quickly it is 

 converted into sugar, the less will be the loss sustained by 

 contact with the soluble salts, for the removal of which 

 there is no convenient process. 



The second method of defecation is exceedingly simple, 

 and requires only a single set of clarifiers ; but the liquor 

 must be afterwards filtered through animal charcoal. The 

 cane-juice, after flowing from the mill through strainers, as 

 in the former method, should be immediately brought to 

 ebullition, and after smartly boiling for a couple of minutes, 

 and removing all the scum which rises, the liquor should 

 be accurately neutralized with milk of lime, which has the 

 effect of coagulating the caseine, but at the same time redis- 

 solves a portion of the albumen and chlorophylle, and if 

 at all in excess, forms a saccharate of liine, with a por- 

 tion of the sugar. These injurious consequences, however, 

 are all obviated by filtration through animal charcoal, 

 which retains the organic impurities, and decomposing the 

 saccharate of lime, sets free the sugar, which passes through 

 nearly in a state of purity, w T hile the lime is retained in the 

 filters. After this process, the liquor, as before, contains 

 only the sugar and the soluble salts of soda and potash, 

 and should at once be conveyed to the evaporating vessels. 



