99 



thing a little more carefully cleaned than is customary, it was found 

 that 500 kilos of cane about to enter the mill carried with it 18.5 kilos 

 of dry trash. Assuming that on the average 2 parts of fiber will be 

 introduced into the mill with every 100 parts of clean cane, we can 

 calculate the effect produced on the composition of the cane and the 

 results obtained in milling as given above. 



. 12.02 „ „, 87.28 



The cane as ground will then contain ^^^ =11.79 per cent fiber; ^„ =85.56 



2.70 

 per cent juice, and yx^=2.65 per cent water other than juice, and the loss of 



juice in bagasse will be 178.5X0.1179=21.05 per cent on the cane, leaving an 



extraction of 64.51 out of a possible 85.56, and a loss in per cent on the total 



21.05 j 



sugar (or total juice) of r,f. ^^ =24.60. 



In grinding a very hard cane, such as the black variety grown to 

 some extent in San Carlos, the losses would be greatly increased. 



Sample number 41, for instance, shows on analysis, fiber, 14.07 per cent; 

 sucrose, 15.02 per cent; and sucrose in juice, 19.18, corresponding to a juice 

 content of 81.43 per cent. Addition of 2 per cent fiber as trash would make the 

 cane as ground contain 15.75 per cent fiber and 79.84 per cent juice. Assuming 

 the average mill efliciency, there would be lost per 100 parts cane 178.5X0.1575 = 

 28.11 parts juice, giving an extraction of only 51.73 out of a possible 79.84 per 

 cent and a loss in per cent of total sugar of 35.22. 



In round numbers, then, it may be stated that the average planter of 

 Negros loses in bagasse about 25 per cent of the total sugar present 

 in the cane. In extreme cases, with very soft and tender cane, this 

 may fall as low as 20 per cent, and when grinding very fibrous cane 

 it may rise as high as 33 per cent. The extraction of juice on the 

 weight of the cane may range from 50 to 70 per cent, but averages 

 about 64.5 per cent. Therefore from 100 tons of cane there are ob- 

 tained 64.5 tons of juice. This is rather better than the rsults obtained 

 in most countries where sugar is produced by primitive methods 

 (Watts ^* states that in Barbados the crushing ranges from 53 to 60 

 per cent), but should be attributed not to any superior efficiency of 

 the mill in Negros, but solely to the free-milling qualities of the cane 

 grown here. 



MANUTACTXJBE OF SUGAR FROM THE JUICE. 



Arrangement of the sugar house. — The sugar-boiling plants of Negros 

 consist essentially of a battery of hemispherical iron vessels or "cauas," 

 uasually five or six in series, in which all the operations of tempering, 

 clarifying, concentrating the juice, and boiling the resultant sirup to 

 a concrete are performed. 



The "cauas, which may be anywhere from 40 to 80 inches (1 to 2 meters) 

 in internal diameter, measured from a short distance below the top, where the 



^* Loc. cit. 



