CHINESE AND AFRICAN SUGAR CANE. 
365 
juice, the longer it must be boiled, and the greater the heat re¬ 
quired, and therefore the darker and finer the grains of sugar. 
Acetic acid, we have shown, cannot be removed bj lime. On 
the contrary it will evaporate like alcohol, with the water in 
boiling. Any one may test this experiment by adding distilled 
vinegar to a solution of sugar and evaporating the mixture at 
boiling heat. The sugar will remain nearly intact. 
To repeat: lime should not be used merely to neutralize the 
vegetable acids; 2d, if acetic acid be present, quick lime should 
not be used at all, as its action is highly injurious; 3d, its ac¬ 
tion on the impurities in the juice is equally so; 4th, by acting 
on the sugar in the formation of gum and glucose, it increases 
the quantity of molasses, and injures the quality of the sugar; 
and lastly, it is unfit as a clarifier except to separate the starch. 
Such are the deductions made by Simmonds, in a long series 
of experiments, and they are confirmed by Wray, Scroffern, 
and Benjamin. So great are these objections, that some plant¬ 
ers are making up their crops in the vaccuum pans, without the 
use of lime. These last find other obstacles equally difficult 
to overcome, by which their loss of sugar is about as great as 
where lime is used. 
To obviate these difficulties, many other substances have 
been resorted to, only a few of which will be noticed. 
A few years ago a patent was applied for at Washington, to 
use acetate of lead as a defecator. The rationale of this pat¬ 
ent was, that acetate of lead would be decomposed by the heat 
of the boiler, when the acetic acid would escape, and the lead 
base would unite with the fibrine and other impurities and pre¬ 
cipitate them in a filter. But the patent was refused by the 
Department on the ground of the danger attendant upon the 
use of so virulent a poison as sugar of lead, or even lead oxyd, 
in the manufacture of sugar. 
Another substitute was supposed to have been found in the 
sulphate of aluminum. To the use of this salt there were two 
objections, which must preclude its use. 1st. The difficulty of 
procuring the salt will always make it command about one*kalf 
