64 MANUFACTURE OF SUGAR IN BARBADOES. 
The most economical and advantageous mode of heating 
the vessels of a sugar establishment, would undoubtedly be 
by the use of steam — a single boiler, or set of boilers, ac- 
cording to the size of the works, furnishing steam to each, 
exactly as may be required, being shut off in a moment 
when no longer wanted, and directed elsewhere with equal 
ease. To heat the vacuum-pan, steam must be used; power 
is required to work the air pump, or to set in motion the 
wheel, in Gadesden's apparatus. To furnish enough steam 
to heat, in addition, the defecating and evaporating vessels, 
will not involve a very great increase of boiler-space or 
consumption of fuel, and will be attended with the very 
great advantage of permitting the application of the whole 
of the megass to the soil as manure. At present, coal can- 
not be landed at Barbadoes from EnHand under 30s. or 35s. 
per ton; even at this high price its use would be, without 
doubt, economical. It might probably be obtained much 
cheaper from Cape Breton in British North America, or 
from the United States. The extensive exportation of coal 
from England is a policy so questionable, that diligent 
search should be made in other available quarters for this 
invaluable fuel, a scarcity of which may, ere very many 
more years have past, be felt at home. — Pharm. Jour. 
ART. XIV. — ON THE MANUFACTURE OF OXALIC ACID. 
By Mr. Lewis Thompson. 
As no accurate account, of the decomposition which 
ensues in the manufacture of oxalic acid has yet been pub- 
lished, that I am aware of, the following experiments may 
tend perhaps to draw attention to this subject. 
The apparatus employed, consisted of a large glass retort, 
placed in a water-bath, and luted to a tubulated receiver, 
from the opening in which a tube passed into a two-necked 
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