Filter and Prepared Charcoal of M. Dumont. 349 
erty of modifying or weakening the action of those pe em 
tained in the syrup which are capable of reacting upon the sugar 
during the boiling. He, therefore, advises the filtration of a third 
or fourth quantity of syrup through the same charcoal, oe that 
afterward they may be crystallized much more readily. 
Long experience only can demonstrate the value of this opinion; 
we can, however, cite one fact which appears to confirm it. A 
syrup of beets which had passed through a partially exhausted char- 
coal without losing any of its dark color, took the fire much better and 
crystallized more readily than a portion of the same syrup unfiltered. 
M. Dumont’s filters are of different sizes. The small contain 
from twelve to fifteen pounds of charcoal, and the large as much as 
two hundred pounds. By them, syrups of all densities from the least 
to the greatest, may be filtered. 
Syrup of 28° to 30° of the areometer filters very well cold, 
those of 36° to 38° require to be poured in hot, andthe charcoal 
coarser, as before stated, the operation lasts about the same te 
the product is not so well decolorized. 
- The syrup of swelve: —— Foams of — can ote om sag in 
apt. four hours. 
- Why are the syrups filtered by M. Durador more deiner tel 
those operated upon the old process? Several reasons can be assign- 
ed in reply. It is easy to conceive, that syrup, in passing through 
the different layers of the column of charcoal should deposit a por- 
tion of its coloring matter in each layer, thus producing greater effect 
than in the bi: and shallow filters used in the old process. Be- 
sides, it is not improbable that the ebullition of a syrup with charcoal 
counterbalances, in part, the decolorizing action of the agent; per- 
haps the caloric effects a reaction of charcoal upon the syrup whieh; 
in destroying one coloring principle elicits another: for the « 
ation is uniformly more perfectly effected without heat. — With re- 
gard to the superiority in point of taste, of the syrups filtered by M. 
Dumont, over those which have been boiled with charcoal, it is 
much more easily to be comprehended, it being an incontestable fact, 
that animal charcoal imparts to syrups with which it is heated, a dis- 
agreeable flavor ;—a flavor which increases with the proportion of 
charcoal. 
On the other hand, M. D. removes from the charcoal a large pro- 
Portion of the soluble matters by means of: the water with which he’ 
moistens it. He operates without heat, which is is another reason 
why his syrups should not acquire any bad flavor. If for per! 
