514 



CHAPTER XXV 



temperature of 84° F., for each one part of water 2-125 parts of sugar are 

 dissolved in a saturated solution. This last determination gives data to 

 calculate the weight of washing syrup which has replaced the molasses. 

 An example is appended. 



Weight of massecuite, 200 grms. ; weight of washed crystals, 175 grms. ; 

 percentage of water in washed crystals, 7 • 54. Then total moisture in washed 



crystals, -^ — = 12-62, and wash liquor in washed crystals — 



100 



12-62 X 3-125 ^— 35-77 grms., and weight of crystals 175 —35-77 =139-23 

 grms., or 69-66 per cent, on weight of massecuite. 



Dupont's Method J^ — Heat the massecuite to a temperature of 80° C. 

 and centrifuge in a small hand machine, the wire basket of which is covered 

 with thin flannel, or some similar material ; polarize the molasses and the 

 cured sugar and calculate the percentage of crystallized sugar from the fol- 



lowing formula : x 



Fig. 339 

 - P' 



/>/ W 



Fig. 



340 



where x = weight of crystallized sugar in 



P'-P" 

 one part of massecuite, a the percentage of sugar in the massecuite, p the 



percentage of sugar in the cured crystals, and p' that in the molasses. 



This formula is applicable for use on the factory scale, provided no water 



is used in curing, and that the molasses are filtered through flannel before 



analysis, so as to remove fine crystals ; if water be used in small quantities, 



and if the amount can be calculated, the sugar percentage of the molasses 



can be corrected for dilution, but, in this case, the formula will not give 



results so correct. 



Geerligs' Method.''^— This method depends on the observation that sugar 

 crystals themselves only contain a trace of ash, the ash of commercial sugars 

 being due to the accompanying molasses ; hence, in a massecuite, the ash is 

 due solely to the molasses. Determine the percentage of ash in the masse- 

 cuite and in its molasses freed from fine grain by filtration through glass wool; 

 as an example, let the massecuite contain 2 - 25 per cent, and the molasses 

 6-07 per cent, ash; then the percentage of molasses in the massecuite is 



2 ■ 25 . , 



^ X 100 = 37-07 per cent. ; the remainder 63-93 per cent, bemg crystal- 

 lized sugar. 



