due was then
repeatedly washed with small quantities of water, until the washings no
longer affected litmus-paper. The oily matter adhered to the capsule
during this process, no part of it coming off with the washing, and at
the end of the washing the capsule and contents were again dried and
weighed, and the weight subtracted from the original weight. The
difference was taken as the alkaloid cocaine, and it amounted to 0.077
grm., equal to 0.26 per cent.

Several preliminary assays were made in reaching this method. Some
authorities recommend the very finely powdered mixture of coca and
magnesia, or coca and lime, to be at once exhausted with ether. Others
recommend that the mixture be made into a paste with water, and after
drying on a water-bath that it be then exhausted with ether. This is
better, but neither of these methods were satisfactory.

Finally, 30 c.c. of a well made fluid extract of the same coca was
thoroughly mixed with 8 grms. of caustic magnesia in a capsule, and the
mixture dried on a water-bath and powdered. This powder was then
exhausted, one part by ether and the other part by chloroform, exactly as
in the method given, both parts giving very slightly higher results. As a
check upon the results, the solution of alkaloid washed out was titrated
with normal solution of oxalic acid.

From all this it would appear that this inferior coca of the markets, or
rather the best that can be selected from it, yields about the same
proportion of the alkaloid as was obtained by Niemann and Maisch, but it
has been shown that, by the older processes of assay used by them, much
of the alkaloid was probably lost or destroyed, and that much better
results are generally obtained by the modern process.

Now, since 3 drachms of this coca, or three fluid drachms of its fluid
extract, gave the same physiological, or perhaps therapeutical, effect as
3 grains of caffeine, and as the 3 drachms contained about 0.45 grain of
cocaine, it follows that cocaine is about 6.5 times more effective than
caffeine; but it also follows that the coca accessible, and even the very
best coca, contains very much less of its alkaloid than those articles
which yield caffeine do of that principle.

* * * * *

THE MELLOCO.

ULLUCUS TUBEROSA.--Early last year two tubers of this plant were received
at Kew from Caracas, and from out of doors in a prepared bed in June. The
result of this experiment, to