238 
DECOLORIZATION OF SUGAR. 
frame crossed by thin strips of wood, which is to be so 
formed that when required it may be pressed down upon 
the cotton. 
For the refining of raw sugar, to every thousand pounds 
weight of sugar I add five to six hundred pounds of water, 
one to two pounds of chalk in powder, and half a pound of 
starch (the starch not being absolutely necessary, but 
appears to have a beneficial effect.) 
The sugar is then heated until it boils, and kept boiling 
from eight to ten minutes ; during the time to be well stirred 5 
and the scum or froth skimmed off. The liquor is then 
allowed to pass through a sieve, for the purpose of separating 
the liquor from the coarse impurities. The pouring in of 
the sugar will drive the water out of the prepared cotton, 
which will run off by the cock. This water is to be pre- 
served, so that at the termination of the filtration, it may 
again be poured upon the cotton. 
If the sugar should run off too quickly, the cotton is to be 
lightly pressed down, which operation newly prepared cot- 
ton will generally require, as it is very elastic and spongy, 
but when it has been in use a few times, it loses this cha- 
racter. 
As soon as the sugar has passed through the filter, it 
possesses a very pure and sweet taste, and may now be 
boiled down to the point of crystallization, as the substances 
made use of in this cleansing, clearing, or refining of the 
raw sugar are perfectly neutral with respect to it. Less 
uncrystallizable sugar is produced, and as sugar so treated 
has a very strong tendency to crystallize, great attention 
must be paid to the boiling and claying processes. 
By pouring water into the filter, it can be perfectly cleared 
of the sugar, while the impurities remain fixed in the cot- 
ton; and this will be evident by merely taking the cotton 
out of the filter, and washing it. After it has been perfectly 
cleansed and washed, it may be used again. 
I may observe the cotton may be mixed and even boiled 
