49 
For the extraction of the drug from the leaves, three operations 
are employed : (l) maceration, (2) intermediate precipitation, and (3} 
final precipitation. For maceration, the leaves are placed in four 
tanks, in the first of which they are treated with a 0.5 per cent, 
solution of sulphuric acid. After twenty-four hours, the liquid is 
allowed to flow into the second tank and the first is again filled with 
new leaves and the acid solution. After another interval of 24 hours, 
the contents of the second tank are run off into the third while 
the former is filled from the first as before, the first again receiving 
a new charge. The fourth tank, after another period of twenty-four 
hours, is filled from the third, and the preceding processes with the 
other tanks are repeated. • In this way, leaves in a state for further 
treatment, namely, those originally put into the first tank, are 
obtained at the end of four days. The tincture thus obtained is next 
placed in a strainer, for the purpose of filtration, after which the 
processes of maceration is complete- 
For the intermediate precipitation, the tincture is subjected to the 
action of sodium carbonate in cylindrical vessels. At this stage, 
in order to test if precipitation is complete, a small quantity of the 
tincture is removed, filtered from the cocaine, and the filtrate tested 
with ammonia, when there should be no precipitate formed. The 
obtaining of a precipitate indicates the necessity for the addition 
of sodium carbonate to the tincture in the cylindrical vessels. 
The first operation for the final precipitation is the addition 
of petroleum, the mixture being stirred carefully for three to four 
hours at a very slow rate. At the end of this period the oil, which 
now contains the cocaine, is washed with acid-free water, and then 
treated with acidulated water, the proper amount being determined 
by the testing for precipitation of an aliquot part. During this 
process, the mixture is stirred vigorously for half an hour to forty 
minutes, with the result that the cocaine is transferred from the oil 
to the acidulate water, which can be separated from the former after 
the mixture has been allowed to stand for about a quarter of an 
hour. 
At this stage, the extract is ready for final precipitation, which 
as before is effected with sodium carbonate, the amount required 
being determined by a test with ; n aliquot part of the solution. The 
mixture is then allowed to settle for twelve hours and, filtered while 
being washed with distilled water, to remove any excess of sodium 
carbonate. The wet residue of cocaine is finally subjected to 
pressure, when the drug is obtained as a white paste containing 87 to 
93 per cent. The usual yield is about 2 %tb. of cocaine per day of 
twenty-four hours. 
When inferior leaves are used, the product is brownish in colour 
and has to be subjected to further treatment, similar to the above ; 
this results, however, in the loss of some of the cocaine. A last 
matter of interest is that the approximate cost of producing 1 lb. of 
cocaine is about .£5 — an amount which naturally varies with the 
price that has to be given for the leaves . — Agricultural News , West 
Indies . 
