48 



must 7iot be warm. This process has failed in the hands 

 of some imitators of M. Crespel, from a mistake on this 

 point. M. Dubrunfaut acknowledges that he himself com- 

 mitted it. 



CHAPTER V. 



CONCENTRATION OF THE JUICE. 



For this purpose one or more boilers are necessary, with 

 which the evaporation is begun and finished, in these the 

 juice from the defecating boiler is received clear ; then a 

 slow fire is kept up in the beginning, and some albuginous 

 matter (white of eggs, or blood) added, if it should seem to be 

 required. After this a man must attend closely to the 

 boiler, and manage the fire. When froth appears it will 

 be his duty, to throw a small piece of butter or other grease 

 (which he should have near him) into the vessel, which 

 will immediately cause it to subside, he should also have a 

 ladle to stir it when required. When the juice has reach- 

 ed the proper point, that is to say 26^ of Baumes's areome- 

 ter when boiling, that is 30" when cold, it is time to proceed 

 to the operation of clarifying. 



CLARIFYING. 



The object of this, is to separate the syrup concentrated to 

 30° or near it, from the extraneous matter which it holds in 

 suspension, and moreover to deprive it by clarifying agents 

 ©f all coloring matter, and other foreign substances which 

 were in the juice, or have formed there whilst under the 

 preceding operation, all which matter is injurious to the 

 sugar. Clarification may be divided into two distinct 

 branches, the one chemical, having for its object by clarify- 

 ing agents, such as animal carbon, albumine &c. to purify 



