MITCHELL SUGAR BY EVAPORATION, 371 



which carefully manipulated, equals animal charcoal in de- 

 colorising power, while it communicates no unpleasant smell 

 to the nitrate, and as refuse becomes a valuable cane-manure 

 To return to the subject of these remarks, the Evaporation of 

 Cane-juice. It is clear that whatever the mode employed, the 

 end to be obtained is in all instances the same, namely, to 

 get rid of the superfluous water in the shortest time, aud 

 with least injury to the remaining sugar in other words, to 

 expose the largest surface of liquid to the largest heating 

 surface under such circumstances as do not necessarily involve 

 deterioration of the liquid. Omitting for the present any 

 consideration of Vacuum-pan working, which is the most 

 perfect as well as the most expensive, I shall confine thesa 

 remarks to evaporation from the inclined plane and by the 

 Shower. 



The Inclined Plane or tray was originally described by its 

 Inventor in 1S37, as a shallow trough 6 metres long and 2 

 metres wide, made of copper and heated by steam, with the 

 lower end at such an inclination, that the Beet-root juice 

 when poured on the upper part in a state of " perfect purity" 

 took two minutes and-a-half to reach the lower end, whence 

 it fell in a continuous stream, marking 22J degrees of Beau- 

 me, the temperature on the surface never marking above 72 

 of Reaumur (167 Fahr.) This inclined plane was imper- 

 fectly divided throughout its whole extent by transverse per- 

 pendicular flanges alternately attached to the opposite sides 

 of the tray in such a manner that the liquid in its descent 

 had to traverse the whole breadth of the pan before escaping 

 at the free end of each flange to course along the next one 

 each flange thus acting as a dam or gutter till the liquid 

 reached its free end, descending to the next, and so on, till 



