In proportion as by too rapid clearing the island has become unwooded, the sugar-houses have begun to want fuel. A little stalk (sugar-cane destitute of its juice) used to be employed to quicken the fire beneath the old cauldrons (tachos); but it is only since the introduction of reverberating furnaces by the emigrants of Saint Domingo that the attempt has been made to dispense altogether with wood and burn only refuse sugar-cane. In the old construction of furnaces and cauldrons, a tarea of wood, of one hundred and sixty cubic feet, is burnt to produce five arrobas of sugar, or, for a hundred kilogrammes of raw sugar, 278 cubic feet of the wood of the lemon and orange trees are required. In the reverberating furnaces of Saint Domingo a cart of refuse-cane of 495 cubic feet produced 640 pounds of coarse sugar, which make 158 cubic feet of refuse-cane for 100 kilogrammes of sugar. I attempted, during my stay at Guines, and especially at Rio Blanco, with the Count de Mopex, several new constructions, with the view of diminishing the expense of fuel, surrounding the focus with substances which do not powerfully conduct the heat, and thus diminish the sufferings of the slaves who keep up the fire. A long residence in the salt-producing districts of Europe, and the labours of practical halurgy, to which I have been devoted since my early youth, suggested to me the idea of those constructions, which have been imitated with some success. Cuvercles of wood, placed on clarificadoras, accelerated the evaporation, and led me to believe that a system of cuvercles and moveable frames, furnished with counter-weights, might extend to other cauldrons. This object merits further examination; but the quantity of vezou (guarapo) of the crystallized sugar extracted, and that which is destroyed, the fuel, the time and the pecuniary expense, must be carefully estimated.