156 SUGAR. 



juice by cooling and by rest, and to wash out the clarifiers every 

 second or third time they are filled. Heat and alkalies acting in 

 them upon the accumulated feculencies of one, two, or three 

 charges, dissolve a much larger portion of those feculencies than 

 they can possibly do in the grande. The formation of coloring 

 matter continues during the time of rest, and accordingly planters, 

 after repeated trials, generally agree that juice well clarified in the 

 grande, has a lighter and brighter color, and makes better sugar 

 than that obtained from clarifiers. 



The first object of research should be to find means of clarifying 

 the juice without creating coloring matter. It is said that presses 

 something like those used to press cotton, have lately been suc- 

 cessfully employed in the "West Indies, instead of rollers ; that 

 the juice obtained is much purer, and that a much larger quantity 

 of it is extracted from the cane. If so, this will be a great im- 

 provement, aud the first step of the process I should recommend. 

 Prom juice thus obtained, I have no doubt that all impurities loss 

 soluble than itself may be separated by mechanical means before 

 heat and alkalies are applied, or at least with a very small quantity 

 of alkalies. All other liquids, all fatty substances and oils, except 

 cotton seed oil, are clarified by a very rapid process. Cane juice 

 can no doubt be clarified by similar means, and if this were accom- 

 plished the process of sugar making would be very much sim- 

 plified. 



The clarified juice might then be placed in an evaporator, heated 

 by the waste steam of the engine; then be limed and scummed if 

 necessary, and concentrated to fifteen or sixteen of the prese sirop ; 

 then purified by filtration through animal charcoal, if white sugar 

 was wanted, or by rest for other qualities ; and finally concentrated 

 in vacuum pans of great power, such pans as Mr. Thomas A. 

 Morgan, of Louisiana, now uses, and which, I am informed, are 

 only made in America. 



The superiority of the vacuum pan is not universally admitted, 

 and we are told that in Prance it is superseded by open pan?, 

 similar to those called in America " Mape' s Evaporators." B owever 

 this may be, I cannot help believing that the vacuum pan has 

 many decided advantages over all others. One is manifest ; the 

 sugar may be grained in the pan, and the granulation is completely 

 under the control of the operator. He may accelerate or retard 

 it at pleasure ; he may carry it so far that sugar will not run from 

 the pan, and will have to be taken out of it ; he may so conduct 

 the operation as to increase, almost at will, the size and hardness 

 of the crystals. This last is an indispensable requisite if the prac- 

 tice of draining sugar in pneumatic pans should be adopted. 



The atmospheric pressure is made too powerful for sugars boiled 

 in any other manner ; it breaks and destroys the crystals, and in a 

 very few days sets the sugar to fermenting. 



The pneumatic draining of sugar has many things to recommend 

 it the usual loss by drainage is avoided, sugar is got ready for 

 market day by day, as it is made, and it may be bleached by pour- 



