xii OONTENTS. 
CHAPTER XX. 
CHEMICAL ACTION OF SUBSTANCES USED IN DEFECATION. 
Chemical Influence of Lime upon Sorghum Juice—Defecation 
by Tannic Acid and Albumen—Upon what the Peculiar Ac- 
tion of these Substances, so combined, depends—Conditions 
favorable to the Use of this Method—Another Method of 
Defecation—The Action of the Chemical Compound used— 
The Composition described and the specced to be de- 
rived from its Use : : : . 182 
CHAPTER XXI. 
ANIMAL CARBON, OR BONEBLACK. 
Filtration—Animal Charcoal or Boneblack—Mode of prepar- 
ing it, and the Condition in which it is employed in this 
Process—Properties of the Charcoal in this form—Mode of 
using it—Its Action—Use in removing the Extractive Mat- 
ter and Harsh Flavor—Decolorizes—Promotes Crystalliza- 
tion— Removes any Excess of Lime, Tannin, etc., etc.— 
Separates all Soluble Substances mechanically suspended 
in the Liquid—Mode of restoring the Powers of the Charcoal 
when exhausted— Different Modes of Reburning—New 
Method of Revivification—Substitutes for it in Filtration . 140 
CHAPTER XXII. 
THE ACTION OF HEAT. 
The Influence of Heat upon Cane Juice—Imperfect convection 
of Heat in deep masses of Syrup—How Heat is economized 
by this Method, and its Intensity regulated, according to the 
Effect required at each Stage of the Evaporation—The Tilt 
Pan—Injurious Effects of a Low but Prolonged Heat—Sou- 
beiran’s Experiments—Open-air boiling indispensable up 
to a certain point of Concentration—Payen’s Experience— 
Evaporation by a Water-Bath or by Steam at 212° F.— 
Why injurious—Advantages derived from the use of a 
Vacuum Finishing Pan—Why it cannot come into general 
Use . : ; ; : : : ; . : . 147 
CHAPTER XXIII. 
OTHER METHODS. 
Description of various Methods of Manufacture heretofore 
used or recommended—The Method of Wray described— 
Its Merits and Disadvantages—Its Impracticability — Mel- 
sen’s Method—Specifications—Its Advantages dependent 
upon the presumption that Sorghum and Tropical Cane 
Juice are identical, which is untrue—Further Reasons why 
Bisulphite of Lime, as a Defecator of Sorghum Juice, is of 
no Peculiar Value , ° ‘ ‘ ° ° ° . 155 
