high or low temperature; and the same directions. are applicable to them as were before given for the cane-syrup. We should remember, however, that the poorer the syrup the more stiffly will it require to be concentrated; so that if the syrup which drains from the molasses-sugar be reconcentrated, it should be inspissated as highly as is consistent with its ultimate drainage.

The more stiffly these low syrups are concentrated the greater will be the temperature required for curing the sugar produced from them.

After every consecutive concentration the molasses acquire an increased density. When it becomes equal to 44° Beaumé, crystallisation can no longer be induced.

The drainage which comes away from the first sugar after syruping should be carefully separated from the molasses themselves: it should be returned to the evaporating vessel, and there be mixed with the defecated cane-juice. The drainage from the molasses-sugars or bastards, when syruped, may be mixed with the first quality of the molasses, or it may be thrown into the concentrating vessel at

once.

The sugar obtained from the first molasses ought always to be liquored, and the syrup used for the purpose should be made from the sugar obtained from the cane juice.

Concentrated molasses are sometimes too poor to bear much stirring in the crystallising vessel.

The time required for their crystallisation is in proportion to their richness, and may vary from

twenty-four hours to a week. The drainage should not be suffered to commence until the necessary quantity of grain is fully formed.

It is by producing a superior quality of molasses that one very considerable advantage is obtained by the filtration of the evaporated cane-juice through animal charcoal. When this process has been pursued, the molasses may be concentrated without undergoing any previous treatment. When it has not been resorted to the molasses have a darker colour, and they are more viscid and tenacious, nevertheless they may likewise be reboiled or otherwise concentrated at once, and the sugar produced will be of a tolerably good quality.

But in England molasses are either blown up with fine charcoal and blood, or with alumina : they are then passed through bag filters, and afterwards through deep beds of animal charcoal. In the colonies the filtration through charcoal would be far from economical, as the force of the charcoal would be expended on bleaching a liquid, a portion of which, after the extraction of a profitable quantity of sugar, is destined merely for distillation.

Dark and viscid molasses are much improved by being blown up with a little sulphate of alumina and chalk or lime, in the manner described in the chapter on Defecation. When this is performed, they should be reduced by the addition of a small quantity of water to the density of 32°, 33° Beaumé; and after ebullition in a copper vessel, be passed through bag filters. This operation will not be

urgently required if the molasses be submitted to concentration at as short a period as possible after their separation, and before fermentation has commenced. The results produced by it are, how

ever, always beneficial.

When the last drainage from molasses-sugar becomes at length so poor, as in the judgment of the planter to be unfit for a profitable concentration, it should be conveyed to the still-house to be converted into rum.

The number of times that the molasses may be submitted to concentration will depend upon many circumstances: in the West Indies, twice probably will be the utmost that this operation will be performed, even when the cane-juice is rich: the third runnings in all cases will, there can be little doubt, be most advantageously used for distillation.

When the syrup shows no sign of granulating, this result may often be obtained by stirring through it a small quantity of dry sugar to form nuclei for the crystals.

For the perfect curing of sugars obtained from low syrups, the temperature of the curing-house should be at least 100°, when that point can be obtained without inconvenience; and the air should be as free from moisture as possible.

CHAP. IX.

RECAPITULATION.- · ALTERATIONS REQUIRED IN PRESENT PLANT. ERECTION OF NEW BOILING-HOUSES, ETC.

WE have now gone through all the operations which collectively form the manufacture of sugar from cane-juice. It has been shown that each of them possesses an evident and distinct purpose, on the attainment of which the successful result of the whole will greatly depend. The principles on which their right performance is based have been explained, and the application of those principles has, I hope, been proved to be both easy and simple. My reward will be great, could I be assured that the reader, if he be a planter, will rise from the perusal of the foregoing pages with clearer views than he before had of the theory of his art; that he will have acquired the conviction that it possesses none of those mysterious difficulties with which his imagination has too frequently clothed it, and that he will thereby be encouraged to practise it with pleasure to himself, and with profit to his employers.

Let us again take a short and retrospective view of these operations, the better to impress upon the memory the objects which by their means we wish to obtain.

1. The canes should be cultivated with a view not merely to their size and abundance, but we should, at the same time, by every means in our power, cause them to yield a juice as rich in saccharine matter and as free from all impurities as possible; and to prevent the evil which would result from decomposition of the juice, when cut, the canes should be conveyed to the mill without loss of time.

2. We should attempt to get from the canes the largest quantity of juice, either by improved mills, or by close attention to the fitting, bracing, feeding, &c. of those now in use; by sprinkling the megrass with water, or by exposing it to steam, and by repassing it between the rollers.

3. We must employ the best means in our power to defecate the cane-juice, that is, to make this liquid approximate as near as we can to a solution of sugar and water only. Its speedy exposure to the action of a high temperature must be effected, and the greatest caution must be practised in the administration of the "temper-lime."

4. The defecated liquor should be evaporated to the density of 32° Beaumé, or to any other suitable degree, with the greatest expedition; care being taken at the same time that the carbonisation of even the smallest particle of the sugar be prevented, by constantly preserving in the pan a depth of liquor sufficient to cover that part of it which is exposed to the fire.

5. The object of filtering the liquor through animal charcoal is the more perfect removal from