150 CULTURE OP THE SUGAR BEET. 



at least reducing its power to pass through. The modification consists 

 in the addition of a small quantity of milk of lime to the juice before it 

 passes to the dialyzer, and is said to produce a wonderfully good effect. 

 It has also been found of great advantage to increase the temperature 

 during the process. By these improvements it is claimed that the work 

 is more rapid, there is a minimum loss of sugar, and the liquid obtained 

 is much purer. 



But the latest methods which have been devised, and which are at- 

 tracting great interest in the sugar manufacturing circles of Europe, are 

 those based upon treatment of the molasses with lime in various ways 

 for the production of a basic sucrate, which may be freed from the min- 

 eral and organic impurities by washing with alcohol or hot water, and 

 worked through the regular processes in the factory for separation of 

 the sugar after saturation with carbonic acid. 



These new methods are styled elution or substitution, according to the 

 mode of applying the lime and treatment of the sucrate obtained. The 

 elution method consists of adding quick lime to the molasses in quantity 

 sufficient to produce a pasty mass, which becomes very hot, and upon 

 cooling hardens ; or slaked lime is employed, and the mixture heated 

 to a temperature of about 220° Fahr. The sucrate formed is broken 

 into lumps and treated with successive portions of dilute alcohol to sep- 

 arate the alkaline salts and other mineral or organic impurities, and the 

 purified compound after being freed from alcohol is sent to the satura- 

 tion pans to be worked with the juice from the presses or by itself, as 

 the case may be. 



The substitution method depends upon the insolubility of the sucrate 

 of lime in hot water. In practice, a quantity of thin milk of lime is 

 added to the diluted molasses in quantity slightly in excess of that re- 

 quired for the formation of the sucrate, and the whole heated in closed 

 vessels under pressure and at a temperature of 220° to 230° F. When 

 the sucrate is formed the hot mixture is passed through filter-presses 

 and the solid matter separated. Each time only about one-third of the 

 sugar contained in the molasses and the mother liquor from the filter- 

 presses, after addition of molasses, is treated a second time. The 

 mother liquors are thus returned and successively treated until they 

 contain about as much of potassic salts as the residue (vinasse) from the 

 distillery, when they are discarded to be employed for the extraction of 

 the potash or for direct utilization as a liquid potassic fertilizer. It is 

 claimed that sugar remaining in the waste liquor represents about 6 per 

 cent, the weight of the molasses treated. Dr. Stammer, the great Ger- 

 man authority on sugar manufacture, considers this latter method the 

 most efficacious and economical of any yet devised for separation of the 

 sugar from the molasses. This view is, however, stoutly combated by 

 the inventors of the elution method.* 



The sucrate from the filter-presses, like that from the other processes, 



* See Journal des Faineants de Sucre, August 20, 1879. 



