MITCHELL — MANUFACTURE OF SUGAR. 
18 ? 
hot or cold — the former would have been the more rapid— 
but he had met with an objection to its use which, if not 
•scientific, was at least practical. The vessels he employed 
were of copper, and transmitted the heat so rapidly that the 
attendants were constantly burning their fingers; he did 
not consider it worth while to take any precautions to avoid 
this evil, as he found cold water sufficient for the purpose 
and more economical. The process he adopted was the 
following : Six upright cylinders of copper about 4 feet 
high and 9 inches in diameter, were so arranged as to com- 
municate with each other and with a reservoir of water on 
a higher level ; they were each furnished with guages and 
stop-cocks ; five of these were filled with cane powder, and 
the last with animal charcoal — this last was merely pre- 
cautionary, but not essential to the work. Water was ad 
mitted into No. 1 and retained there for 20 minutes after 
the guage showed that the vessel was full ; it was then 
! passed into No. 2 and so on. In practice it was found that 
1 on escaping from No. 4 the water had absorbed so much 
sugar as to mark 22*5 of Beaume, or about the density 
when syrup is usually consigned to the vacuum pan, and 
that the cane powder first in contact with the water, viz. : 
that in No. 1 was completely exhausted, even to the tongue, 
that most convenient and reliable saccharometer, and re- 
presented what it was reduced to in reality — a mass of wet 
sawdust. At this stage of the process it was removed from 
No. 1 and replaced by a fresh portion of cane powder. As 
this part of the operation was performed without interrupt- 
ing the duties of the other cylinders, it is clear that two of 
the greatest desiderata in the application of Science to Art 
had been attained, namely : the complete extraction of the 
