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in the original juice. (3) Sucrose burned or caramelized during manufacture, 

 together with that first inverted and then completely destroyed by the combined 

 action of lime, lime salts, and excessively high temperatures. (4) Mechanical 

 losses, including juice, sirup, and "massecuite" spilled in the handling, and sugar 

 spilled, stolen, or eaten by the workmen. 



Scmns.- — The per cent of sucrose in the scums, etc., which are thrown away, 

 is always very high, since the juice adhering to these has, by the time clarification 

 is completed, become much more concentrated than the original, raw liquid. A 

 few representative analyses of these waste products will serve to show the con- 

 siderable amount of sugar which may be carried away by them : 



Skimmings from unlimed mill juice in a preliminary clarifying tank. — These 

 consist largely of fine particles of bagasse, mixed with froth and juice, which are 

 thrown into a basket suspended over the tank and allowed to drain without 

 pressure, then thrown away. The sample contained 25.2 per cent total solids 

 and 17.9 per cent sucrose. 



Skimmi7igs from caua No. 5, which were not considered worth pressing, but 

 were thrown away at once, contained 29.3 per cent of total dry substance and 

 22.8 per cent sucrose. 



Filter-press mud. — In this instance a large receptacle located between "cauas" 

 No. 4 and No. 3 served as a sort of settling tank, being filled with hot, partially 

 limed juice from No. 4, which after settling for an hour or so was decanted into 

 No. 3. As in the meantime unclarified juice was continuously being ladled 

 directly from No. 4 to No. 3, the advantages of the system are not obvious. 

 The settlings from this tank, about one-fourth its total volume, were run into 

 sacks, on top of which were placed pieces of old iron, car wheels, etc., and the 

 whole allowed to drain for half a day until it had nearly stopped dripping, when 

 the sacks were emptied of the remaining sludge, which was thrown away. A 

 sample of this sludge was found to contain 23.2 per cent sucrose. 

 . Of course, there are some few factories in Negros where such large losses are 

 not incurred, but the instances cited above represent rather better working than 

 the average, many places allowing scums and settlings to run to waste directly, 

 without any attempt at filtration. 



There are two or three fairly modern, steam-heated filter presses on the Island, 

 but they do not appear to have given universal satisfaction, principally because 

 of the lack of intelligent labor to operate them, and the consequent trouble due 

 to leacks, broken filter cloths, etc. A very simple, and yet fairly efficient form 

 of scum filter found working in the district of Bais consists of a square wooden 

 box of a little over a cubic meter capacity, provided with a perforated double 

 bottom and a plunger at the top, forced down by a very heavy screw. The scums 

 are filled into ordinary flour sacks, which are tied up tightly and piled inside 

 the box; pressure is then brought to bear, at first slightly, but finally with 

 much force, so that the resulting cake is said to come out almost as dry as 

 ordinary filter-press cake. About one hour is required to fill this press, and two 

 and a half hours to empty it, about four presses full, or 4 tons of scums, being 

 treated per day. As fully half of this, containing at least 20 per cent of sucrose, 

 would otherwise be thrown away, the press causes a saving of about 400 kilos of 

 sucrose, or, at the present price of sugar, about 50 pesos per day. The whole 

 affair cost less than 200 pesos to make, including 150 pesos paid for the screw, 

 and, considering the class of labor available for working it, is probably about as 

 efficient for a small factory as the more costly modern filter presses. 



Inversion losses. — With a view of determining the losses occasioned by the 

 conversion of sucrose into reducing sugars, tests were made at two haciendas of 

 the juices and sirups in the various "cauas" covering periods of about half a day 

 each : 



