142 ANIMAL CARBON, OR BONEBLACK. 
2. It decolorizes. Although this, as has already been 
said, is not a primary object, the color of the previously 
clarified syrup being very fine, it is still further improved, 
and the syrup acquires a glassy brightness and purity of 
color not otherwise attainable. 
3. It promotes crystallization in a high degree, and 
increases the quantity and improves the quality of the 
sugar. The ordinary boneblack is said to increase the 
crystallizing property of the juice of the tropical cane in 
a remarkable degree, in some instances 18 to 20 per cent. 
Upon the juice of sorghum its influence, in this respect, is 
very decided. 
4. It removes any small excess of lime which may have 
been added in saturating the free acid in the juice. This 
property of boneblack is practically of much value. To 
insare a perfect neutralization of the acid, and the conse- 
quent coagulation of the albumen, the juice should be 
made to exhibit a faint alkaline reaction—or, in other 
words, a slight excess of lime should have been added. 
This the filter wholly removes. So also it removes any 
excess of tannin or alumina that may inadvertently have 
been introduced. 
5. Independent of the above-mentioned properties, it 
acts as a strainer of the most effective kind for arresting 
any insoluble substances mechanically suspended in the 
liquid, such as compounds of lime and fine particles of 
sand, more or less of which are found in all unrefined 
syrups. 
As the intensity of the action of the carbon may be 
modified indefinitely according to the state of division to 
which it is reduced, the density and temperature of the 
syrup, and the nature and quantity of the impurities which 
the syrup contains, the boneblack must conform, when used 
as above, to a certain standard in quality and properties, 
and it must be used in the manner already described. 
