SUGAR 943 



process lasts several weeks, the claying-house requires to have very considerable 

 dimensions. Whenever the syrup is properly granulated, which happens usually in 

 about 18 or 20 hours, the plugs are removed from the apices of the cones, and each 

 is set on an earthen pot to receive the drainings. At the end of 24 hours the cones 

 are transferred over empty pots, and the molasses contained in the former ones is 

 either sent to. the fermenting-house or sold. The claying now begins, which consists 

 in applying to the smoothed surface of the sugar at the base of the cone a plaster of 

 argillaceous earth, or tolerably tenacious loam in a pasty state. The water diffused 

 jimong the clay escapes from it by slow infiltration, and descending with like slow- 

 ness through the body of the sugar, carries along with it the residuary viscid syrup, 

 which is more readily soluble than the granulated particles. "Whenever the first 

 magma of clay has become dry, it is replaced by a second ; and this occasionally in 

 its turn by a third, whereby the sugar-cone gets tolerably white and clean. It is 

 then dried in a stove, cut transversely into frusta, crushed into a coarse powder on 

 wooden trays, and shipped off for Europe. Clayed sugars are sorted into different 

 shades of colour according to the part of the cone from which they were cut. The 

 clayed sugar of Cuba, which is sun-dried, is called ' Havannah sugar/ from the name 

 of the shipping port. 



Clayed sugar can be made only from the ripest cane-juice, for that which contains 

 much gluten would be apt to get too much burned by the ordinary process of boiling 

 to bear the claying operation. The syrups that run off from the second, third, and 

 fourth applications of the clay-paste, are concentrated afresh in a small building apart, 

 called the refinery, and yield tolerable sugars. Their drainings go to the molasses- 

 cistern. The cones remain for 20 days in the claying-house before the sugar is taken 

 out of them. 



Claying is seldom had recourse to in the British plantations, on account of the 

 increase of labour, and diminution of weight in the produce, for which the improve- 

 ment in quality yields no adequate compensation. Such, however, was the esteem in 

 which the French consumers held clayed-sugar, that it was prepared in 400 plantations 

 of St. Domingo alone. 



SUGAR REFINING. The raw or Muscovado sugar, as usually imported, is not in a 

 state of sufficient purity for use. The sugar is blended with more or less of frtiit- 

 and grape-sugars, with sand and clay, with albuminous- and colouring-matter, chiefly 

 caramel. To separate the pure sugar, the plan formerly adopted was to add blood, 

 eggs, and lime-water to a solution of the raw sugar, and after applying heat, to 

 remove the thick scum of coagulated albumen, which also removed a considerable 

 portion of colouring-matter. The clear liquid was concentrated, and the semi- 

 crystalline mass being placed in conical moulds, as much of the molasses as would 

 drain by gravitation was allowed to escape from the points of the moulds, and the 

 remainder was expelled by allowing water or a solution of pure sugar to trickle 

 through the mass of crystals. The loaves, being trimmed into shape and dried, 

 were fit for sale. 



By this process only a small proportion of the sugar was made into loaf. The 

 method of removing the colouring-matter was crude, imperfect, and expensive ; and 

 the high temperature requisite for the fermentation of the syrup not only injured 

 its colour, but converted a large proportion of the sugar into the uncrystallisablo 

 variety. 



These defects were remedied, to a great extent, by the adoption of Howard's 

 vacuum-pan, for the concentration of syrups under diminished atmospheric pressure, 

 and consequently at a low temperature together with, the use of filtering-beds o.f 

 animal-charcoal for the removal of colouring-matter. 



There are three classes of sugar-refineries in this country, the chief productions of 

 which are, respectively : 



1st. Loaf-sugar. 



2nd. Crystals (i.e. large, well-formed, dry white crystals of sugar). 



3rd. Crushed sugar. 



In the former two, good West India, Havannah, Mauritius, or Java sugar are 

 almost exclusively used. In the last, all classes of sugar are indiscriminately em- 

 ployed. The manufacture of loaf-sugar is chiefly carried on in London ; of crystals, 

 in Bristol and Manchester ; of crushed sugar, in Liverpool, Greenock, and Glasgow. 

 Besides these places, which are the chief seats of the sugar-refining trades, this 

 branch of industry is carried on more or less at Plymouth, Southampton, Goole, 

 Sheffield, Newton (Lancashire), and Leith. The methods vary a little in different 

 refineries ; but the following description refers to the most modern and best conducted 

 which are to be found in this country. The general arrangements of a sugar-house 

 are shown in Jig. 1930. 



LoAF-StTGAB. Solution. The raw sugar is emptied from the hogsheads, boxee, 



