PURIFICATION OP COTTON OIL. 
297 
ART. XLIX.— PURIFICATION OF COTTON OIL. 
The purification of cotton oil is of such vast importance for 
this and the countries where the cotton plant is cultivated, 
that frequent endeavours have been made to render this oil 
useful in domestic economy, but these have invariably proved 
abortive, in consequence of the experimenters making use of 
processes employed for a long time in the clarification of certain 
oilsof Europe, whilst the oil of cotton differs materially from all 
other oils. It is useless to try to purify it thoroughly. Indeed 
the quantity of elaine is so much less than the proportion of 
stearine, that it gives to this oil an almost butter-like con- 
sistence, which alone presents an obstacle to its use in 
affording light. Independent of this, the impure oil of cotton, 
such as is received from Natchez, contains a very considerable 
quantity of mucilage, and also carbon, which still increases 
its density. 
After several trials, I have come to the conclusion that it is 
necessary to separate the elaine from the stearine to render 
the oil combustible; an object which can easily be attained by 
adding, to a given quantity of oil, a sufficiency of boiling 
alcohol to dissolve the greater part. Decant, and submit to 
distillation without awaiting its becoming cool. The alcohol 
always carries off from the mass a little colouring matter, 
which gives to the elaine a brownish tint, but which may 
be easily removed by treating it anew with alcohol, and 
fiiltering the oil through coarsely bruised animal charcoal. 
As to the stearine forming the residue, by adding certain 
proportions of yellow wax and plumbago, it may be used as 
a composition for greasing carriage wheels. It may likewise 
be saponified, and an impure soap made. At first sight, this 
process may seem costly, but it is easy to perceive that at 
each distillation scarcely one-tenth of the alcohol is lost. 
With an advantageous profit, this oil can then be passed over 
to commerce at a price far below that of the spermaceti oil. 
Dr. James Trudeau, of New Orleans, and latterly a resi- 
