334 CliYMISTRY APPLIED TO AGRICULTURE. 



to moisten tlie sides of the boiler, and then blowing forci- 

 bly into a skimmer which has just been immersed in it ; if 

 bubbles escape through the holes of the skimmer which 

 ascend into the air in the same manner as soap bubbles do, 

 the liquor is considered to be sufficiently boiled ; the fire is 

 therefore immediately extinguished, and the siru|) is a few 

 minutes after conveyed to a great copper boiler, which is 

 called the cooler. 



The cooler is placed in an apartment of the manufac- 

 tory near the boilers ; its capacity should be such as to al- 

 low of its receiving the product of the four successive 

 boilings. The cooling which the sirup experiences in this 

 vessel, quickly produces crystallization; the crystals form 

 first at the bottom, where they collect in a thick bed, hav- 

 ing, however, no union of particles. Gradually the sides 

 become covered with solid crystals, and at length there is 

 formed upon the surface a crust of sugar which thickens 

 insensibly. At this time the contents of the cooler are 

 taken out to fill the moulds in which the process of crys- 

 tallization is to be completed.* 



The contents of the cooler are first thoroughly stirred 

 and mixed, and then thrown gradually into the moulds, a 

 portion being put into each in turn, so as to fill them all 

 equally : an interval of an inch is left between the surface 

 of the sirup and the top of the mould. 



Crystallization is hastened by carrying the moulds, as soon 

 as they are full, into the coolest apartment of the manufac- 

 tory .t 



* The moulds used in this operation are known in refineries by the 

 name of grandes hatardes. They are large conical vessels of baked 

 earth, with a small opening at the apex, and capable of containing 

 about 100 pounds of the evaporated sirup. The different sizes are 

 distinguished in the manufactories as grandes et petites hatardes, ac- 

 cording to their different capacities ; they are numbered 1, 2.3, 4, &c. 

 Moulds made of resinous wood have supplied the place of these in 

 some manufactories ; this change was proposed by M. Mathieu de 

 Dombasle, and in those countries where wood is abundant, it is a good 

 one in point of economy. 



The moulds must be soaked in water, and then drained, before the 

 sirup is put into them } the opening at the point is stopped vv^ith old 

 linen, and the vessels themselves supported against the walls to re- 

 ceive the liquor. 



t The sirup arising from the employment of 10,000 pounds of beet 

 roots, if the operations are well conducted, will fill nine grandes ha- 

 tardes, each bdtarde containing from 85 to 90 pounds of evaporated 

 sirup. 



When the different boilings are made slowly, or experience any in- 

 terruption, the moulds are partially filled from the cooler, without 



