338 CHYMISTRY APPLIED TO AGPvICULTURE. 



large quantities. I have always observed that when I sub- 

 jected to the same refining process 2000 or 3000 lbs. of 

 sugar, the last boilings were ropy, and each operation less 

 perfect than when performed upon 400 kilogrammes (about 

 890 lbs.) at one time: it is upon this last quantity that I 

 shall found my calculations.* 



ARTICLE I. 



On Clarification. 



A BOILER four or five feet in diameter and twenty-eight 

 inches in depth is two thirds filled with water, to which 

 lime-water enough to fill the boiler is added ; in this mix- 

 ture is dissolved at a low heat 400 kilogrammes of brown 

 sugar. 



The solution must not mark more than 32° (=z 1.286) 

 of concentration ; if it stands higher, it must be weakened, 

 if lower, more sugar must be added. This state of con- 

 centration belongs only to solutions of dry sugar ; those 

 of damp sugar must be reduced to 30° or 25°, (=: 1.261 

 to 1.210,) otherwise it will be almost impossible to filtrate 

 them. 



The solution is then heated to ebullition. When the tenj- 

 perature reaches 65° (i= 178^° Fahr.) fifteen kilogrammes 

 (32|^lbs.) of animal charcoal are added to it; the mixture 

 is then carefully stirred and mixed with a wooden spatula; 

 ajfter allowing it to boil an hour, the fire is extinguished. t 

 The boiling liquor is freed from the charcoal by filtration 

 through a coarse cloth, and when the heat has fallen to 

 40°, (122° Fahr.,) the whites of forty eggs beaten and 

 diluted with several quarts of water are thrown into the 



* I have never been able to assign a reason for this difference, but 

 it actually exists ; perhaps it arises from my not being able to com- 

 plete ray boilings in one day, and the clarified sirups having become 

 changed in the boiler ; or perhaps a large quantity of sirup may be 

 more difficult to manage than a small one, though the ingredients be 

 combined in the same proportions. 



t The quantity of animal charcoal added ought to vary according 

 to the quality of the sugar ; that which is dry requiring a less portion 

 than that which is wet. 



