CLARIFICATION 55 



sweet and fragrant, with a pleasant flavour of the 

 sugar cane. But when the home refiners produced 

 yellow sugar with a pale primrose tint the poor old 

 muscovadoes were thrown rather into the shade. Then 

 came the new raw sugars from our colony of Demerara 

 which soon cut out all competitors. They were crystal- 

 lized in the vacuum pan and had a large bold crystal of a 

 pretty yellowish tinge. Trinidad followed the example 

 of its neighbour, then came St. Lucia, and now many 

 more imitators. 



There is no secret now as to the method of preparing 

 the juice for making this sugar. A few words are 

 sufficient to give the general reader an idea of the 

 special preparation of the juice when " yellow crystals " 

 are to be made. There is a gas called sulphurous acid, 

 the product of burning sulphur, which has the property 

 of bleaching vegetable substances. In the days when 

 sulphur matches existed boys used to light one and 

 hold a flower over the smoke to see it turn white. The 

 cold juice from the mill, heavily limed, is pumped to 

 the top of a tower or vertical box, where it runs down 

 the inside over a series of perforated trays which scatter 

 the juice in a shower. Sulphurous acid gas is intro- 

 duced at the bottom under pressure, so that the juice 

 and the gas thoroughly mingle. While the juice is 

 descending the gas is rising to the top of the tower. An 

 alternative system is to blow the gas through perforated 

 pipes into the bottom of a tank full of cold limed juice. 

 The effect of these processes is to nearly neutralize the 

 lime with sulphurous acid. The viscosity is greatly 

 reduced and the subsequent work of crystallization 

 and " curing " greatly facilitated. The juice must 

 not be heated until neutralization is nearly complete. 

 The action of the acid on the cold limed juice is to bleach 

 it, and to break up the organic soluble salts, substitut ing 



