THE DETERMINATION OF CANE SUGAR 



497 



Brix spindles, as purchased from reliable dealers, are generally of con- 

 siderable accuracy. Nevertheless, each instrument should be standardized. 

 This is most readily done by reserving one special set as a carefullv checked 

 standard against which newly purchased instruments can be compared. 



Special Points in connection with Sugar House Products.— Raw juices 

 from the miUs carr}^ in suspension much solid matter and are also emulsioned 

 with air. As a preliminary, they should be strained through gauze, allowed 

 to stand for some time to allow the heav}- particles to subside and the air 

 and lighter solid particles to rise. The intermediate portion may then be 

 drawn off into the cylinder in which the observ'ation is made. A vessel 

 with a cock located about two inches from the bottom is convenient and this 

 vessel should contain two to three times the volmne of the cylinder. Molasses 

 and massecuites cannot be observed directly. The usual convention for 

 process control is to dilute wdth an equal weight of water, obser\'e the Brix 

 of the diluted material and multiply by two. This determination is of 

 sufficient exactitude for controlling the manufacturing processes, but it does 

 not give exact data to determine the " weight per cubic foot." 



When the density of the undiluted material is required, the following 

 procedure may be adopted : — 



A large wide-mouthed vessel of the shape shown in Fig. 330 is 

 constructed of copper or brass, or even a wide-mouthed bottle 

 may be employed. The mouth of the vessel is best formed 

 sloping inwards, so that a stopper ma}^ be ground accurately to 

 fit this mouth. Through the centre of the stopper is bored a 

 hole about |-in. in diameter. Massecuite from the pan is 

 allowed to fiow into the vessel until about seven-eighths full ; 

 the vessel is then allowed to cool until it has reached the 

 temperature at which the factor}' measurements of massecuite 

 are taken, and the weight of massecuite determined. Water is 

 then carefully poured over the siurface of the massecuite till the vessel is 

 full, the stopper inserted, when the excess of water escapes through the 

 aperture and is wiped off. The method of calculation is shown below : — 



Fig. 330 



Weight of vessel and stopper emptv 



,, ,, ,, and water 



water 



vessel, stopper, and massecuite 

 massecuite 



vessel, stopper, massecuite, and water 

 water above massecuite 

 water in space occupied by massecuite 



Apparent specific gravity of massecuite 



2229 -60 



Grms. 



416 -35 

 2163 -40 

 1747 05 

 2645 -95 

 2229 -60 

 2875 -95 



230 -oo 

 1517-05 



I -469 



In using this method no attempt is made to remove imprisoned air- 

 bubbles, the object of the determination being to facsimilize the actual 

 working of the factor^'. 



An accurate determination of actual specific gravity of a massecuite can 

 be made by this method, using instead of water an indifferent material such 

 as oil. This is introduced into a wide-mouthed vessel similar to the one 



2L 



