138 POPULAR ECONOMIC BOTANY. 



the molasses is merely separated by draining, the sugar is 

 then termed Muscovado. 



Lately a mechanical process for cleaning sugar from the 

 molasses has been invented and patented by Mr. Leonard 

 Hardman, of Liverpool, and others. It consists of an iron 

 cylinder, pierced all over with small perforations ; the sugar 

 to be cleaned is put into this cylinder, which is made to re- 

 volve with great velocity; in the axis of the cylinder is a 

 passage by which atmospheric air is drawn in, and passes 

 with great force through the sugar, carrying out with it the 

 molasses, which flies through the perforations; the whole 

 being enclosed in an iron chamber, the molasses falls to the 

 bottom, and drains off through a proper channel into a re- 

 ceiver : by this process the darkest sugar is rendered as dry 

 and light-coloured as the finest clayed sugar. The refining 

 of sugar is a process by which the remaining treacle and 

 colouring matter is entirely removed, the bleaching being 

 effected chiefly by the agency of animal charcoal and im- 

 proved crystallization, by successive boilings and slow cool- 

 ing at a regulated temperature. 



Raw sugar is imported from the West Indies in large 

 casks called hogsheads, in smaller ones called tierces, and in 

 barrels ; from the East Indies in bags, chiefly made of jute- 



