80 NUTRITIVE PLANTS. 



serted, compressed, squeezed till all their juice is obtained from 

 them, and are themselves, sometimes, even reduced to powder. 

 One of these mills, of the best construction, bruises canes to such a 

 quantity as to afford in one day, 10,000 gallons of juice, when 

 wrought with only ten mules. The expressed juice is received into a 

 leaden bed. It is thence conveyed into a vessel called the receiver. 

 The juice is found to consist of eight parts of pure water, one part 

 of sugar, one part of oil and gummy mucilage. From the greener 

 parts of the canes there is apt to be at times derived an acid juice, 

 which tends to bring the whole unseasonably into a state of acid fer- 

 mentation. Fragments of the ligneous part of the cane, some por- 

 tions of mud or dirt, which unavoidably remain on the canes, and a 

 blackish substance called the crust, which coated the canes at the 

 joints, are also apt to enter into contaminating mixture with the 

 juice. From the receiver the juice is conducted along a wooden 

 gutter, lined with lead, to the boiling-house. In the boiling-house it 

 is received into copper pans, or cauldrons, which have the name of 

 clarifiers. Of these clarifiers the number and the capacity must be 

 proportioned to the quantity of canes, and the extent of the sugar 

 plantation on which the work is carried on. Each claritier has a 

 syphon or cock, by which the liquor is to be drawn ofF. Each 

 hangs over a separate fire : and this fire must be so confined, that 

 by the drawing of an iron slider, fitted to the chimney, the fire may 

 at any time be put out. In the progress of the operations, the 

 stream of juice from the receiver fills the clarifier with fresh liquor. 

 Lime in powder isadded, in order to take up the oxalic acid, and the 

 carbonaceous matters which are mingled with the juice. The lime 

 also in the new salts, into the composition of which it now enters, 

 adds itself to the sugar, as a part of that which is to be retained by 

 the process. The lime is to be used in the proportion of somewhat 

 less than a pint of this substance to every hundred gallons of li- 

 quor. When it is in too great quantities, however, it is apt to de- 

 stroy a part of the pure saccharine matter. Some persons employ 

 alkaline ashes, as preferable to lime, for the purpose of extracting 

 the extraneous matter; but it is highly probable that lime, judiciously 

 used, might answer better than any other substance whatsoever. 

 The liquor is now to be heated almost to ebullition. The heat dis- 

 solves the mechanical union, and thus favours the chemical changes 

 in its differens parts. When the proper heat appears, from a rising 



