THE ASSAY OF SUGAR HOUSE PRODUCTS. 



Glucose is determined in the extract obtained as above. 



Ash is obtained by incinerating at a low red heat a portion of the finely- 

 divided cane. 



Water is determined by drying to constant weight, preferably in vacuo. 



Fibre is determined by repeatedly exhausting with water the megass 

 obtained in sugar method 1, or the finely divided cane, and drying the 

 exhausted residue to constant weight. 



When analysing cane or canes, it is of essential importance to remember 

 that the cane is not of uniform composition, and a sample must represent the 

 whole length of the cane. When making systematic control analyses of cane, 

 the writer has pursued the following method : A factory was grinding sixteen 

 car-loads per hour ; from every car-load one cane was selected ; when sixteen 

 canes were thus obtained, the top sixteenth was cut from the first, the second 

 sixteenth from the second, and so on ; each piece of cane was then split 

 longitudinally with a sharp knife, first into halves, then one half into quarters, 

 and finally into eighths ; from the sixteen canes a sample weighing on an 

 average 200 300 grms. was obtained representing each portion of the cane. 

 Proceeding systematically on these lines, as many as 100 canes can easily be 

 analysed in a day of eight hours. 



Analysis of Megass. Water. The determination of water in 

 megass so as to obtain figures representative of the working of the mills is a 

 problem which is not so easily solved as at first sight appears. The chief 

 difficulty lies in obtaining a sample of a bulk convenient for analysis and at the 

 same time representative of the many tons of megass made in a day. In the 

 writer's experience the very smallest sample for the actual analysis that can be 

 obtained is one of about 50 grms. weight, obtained as a sub-sample from one 

 of several kilograms taken across the whole width of the rollers. Megass is a 

 material which is exceptionally retentive of moisture, and when dried under 

 atmospheric pressure at the temperature of boiling water is completely dried 

 only after heating for long periods. The time taken for drying depends very 

 largely on the way the material is arranged in the oven ; the drying is quicker 

 the greater the surface exposed. The writer has found shallow tin trays about 

 4-5 inches square and half an inch deep very suitable. Such trays easily hold 

 50 grms. of megass, exposing a large area ; gauze baskets or linen bags do not 

 give such good results as regards time occupied in drying. When the drying 

 is carried out at atmospheric pressure, a temperature in the oven of 240 F. is 

 necessary if the megass is to be dried within a reasonable time ; megass placed 

 in a layer in a shallow tray will be completely dried in from four to six hours 

 at this temperature. Wherever possible, however, the vacuum oven already 

 described should be used. Spencer 6 recommends that the samples taken for 

 determination of moisture should be about 500 grms., and that it be contained 

 in bags made of mosquito netting. 



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