STJGAE. 16 



be filtered as Mr. Fownes recommends, by which means the 

 liquor would be more effectually clarified, and much, if not all, the 

 subsequent labour of skimming dispensed with. The matter re- 

 maining on the filter may be employed, either as a ferment in the 

 still-house, or added to the manure heap. Much of the beneficial 

 effect of the mucilage of the guazuma arises probably from an 

 admixture of tannin, or some other astringent ; for I have ofben 

 been struck with the peculiar whiteness of the potted sugar n 

 the curing-house, in the immediate vicinity of the Banana stalfcs, 

 resulting, no doubt, from their powerful astriugeiicy ; and tannin 

 has already been found useful in the manufacture of sugar from 

 beet- root in France, and is no doubt equally applicable to cane- 

 sugar. 



The liquor, when clarified in the manner described, must be con- 

 centrated, by regulated evaporation, to the degree requisite for 

 crystallisation. This Mr. Fownes advises to be done by steam of 

 a moderate pressure circulating in a spiral of copper-pipe laid at 

 the bottom of the evaporating vessels, which should be large and 

 shallow, and wholly unlike those in present use. Here it may 

 be rapidly boiled down till the heat rises to about 225 deg., with- 

 out risk of burning. When cold, it should have a density of about 

 V38, and mark the 38th degree of Baume's hydrometer ; beyond 

 which point of inspissation it would be dangerous to go. The re-r 

 maining concentration will be most safely conducted in the vacuum 

 pan, where a scarcity of water does not, as in Barbados, militate 

 against its use. 



Mr. Fownes exposes the absurdity of using shallow coolers, ex- 

 posing a large surface, and producing a rapid evaporation, for the 

 process of crystallisation. By the use of the shallow coolers for- 

 merly, and, I believe, yet to be found on most estates, from the 

 rapidity of the evaporation, the sugar is obtained in a mass of con- 

 fused and imperfectly-formed crystals, entangling in their inter- 

 stices a considerable quantity of molasses, which impairs the color 

 of the product, and escaping slowly, and with difficulty, is, to a con- 

 siderable extent, lost on the homeward voyage by drainage into the 

 hold, occasioning much positive loss to the owner, and giving the 

 bilge-water a most offensive odor. He therefore recommends the 

 use of deep vessels, and avoidance of all agitation in this part of 

 the process, so as to enable the crystallisable portion of the syrup 

 to effect a more complete separation from the uncrystallisable por- 

 tion or the molasses. By this simple method, not only sugar of 

 a finer and whiter quality would be obtained, but a large per cent- 

 age of loss both of crystallisable and uncrystallisable sugar at pre 

 sent caused by the leakage of the hogshead into the hold, would be 

 prevented, not only to the great advantage of the planter, but to 

 the great comfort of the captain, passengers, and crew of the ves- 

 sel freighted with it. 



It is not improbable that, by reboiling the molasses in the va- 

 cuum-pan, and employing tannin in the manner adopted in the 

 process for making sugar from beet-root, from one to five per 



