STATE AGRICULTURAL SOCIETY. 289 



Fotirth — It must then be crystallized. 

 Fifth — The crystals must then be purified. 

 Sixth — The sugar must then be refined. 



■& v 



The following arc the principal methods used in the manufacture of 

 beet sugar at the present time : 



The beet from which the juice is to be extracted must be first cut up. 

 The beets are sometimes cooked previous to this operation, but the more 

 common way is to use them raw. For tbis operation, cutters are used 

 which cut the beets into ribbons or slices, or the root is submitted to the 

 action of a rasp, and a pulp of the proper degree of fineness obtained. 

 The last method is the one generally used. 



The pulp is then submitted to pressure, an operation which is per- 

 formed in various ways. The more common way is to put the pulp into 

 sacks of a coarse woollen material, which are piled in layers upon a 

 frame, each layer being separated by a plate of iron, perforated with 

 holes, or by a grating of the same material, with narrow spaces between 

 the bars. These sacks are then submitted to pressure, which is done by 

 an ordinary screw press, or by an hydraulic press, or by both. The 

 sacks, after being used, are washed and soaked in a weak solution of 

 tannin. 



The pressure, no matter how effectively performed, fails to extract 

 more than seventy-five or eighty per cent, of the juice. As the beet con- 

 tains ninety-eight per cent, of water, sugar and soluble matter, and only 

 two per cent, of residuum, there is a loss by this process of from eighteen 

 to twenty per cent, of juice. To prevent this loss, the extraction of the 

 juice by maceration, or the use of water instead of pressure, has been 

 attempted. Various machines and processes have been used, generally 

 with excellent success, but this method has not as yet superseded the 

 more common method of pressure. 



The name given to the process of purification of the juice is defecation. 

 The object is to remove, as far as possible, the foreign matters remaining 

 in the juice after pressure. These are principally nitrogenous matter, 

 mineral substances, coloring matter, an»d the coagulable albumen. The 

 coagulable albumen is removed by the action of heat, which causes it to 

 become insoluble. To remove the other matters, lime is added. These 

 form, with the lime, insoluble compounds which are easily eliminated, 

 but as an excess of lime combines with the sugar and forms saecharate 

 of lime, which causes a loss of sugar by its becoming dissplved, and as 

 tbis saecharate is injurious to the manufacture of good sugar, being one 

 of the most active causes of discoloration in cooking, and its presence 

 producing sucre </ras, it is necessary to eliminate this excess of lime. 

 Tbis was formerly done by passing the juice through animal charcoal. 

 M. Bassett* observes that he is ignorant what have been the motives 

 which have induced manufacturers to make use of this operation, and 

 remarks that the animal charcoal has no effect on the lime; that it does 

 not act upon the saccharine alkalies; and that its decolorizing power — 

 the only one it possesses — is of no value when the liquid is not free from 

 the ulterior causes of the color, i. e., the alkaline bases. The use of lime 

 in large quantities for the purpose of eliminating the foreign matters 



* Etudes sur l'Exposition de 1867, 3°Fascicule, 30 juin 1867. 



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