Scientific American Supplement, No. 492, June 6, 1885 by Various

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Conflicting and contradictory testimony from competent authority is not
uncommon in therapeutics, and the reasons for it are well recognized in
the impossibility of an equality in the conditions and circumstances of
the investigations, and hence the general decision commonly reached is
upon the principle of averages.

There can hardly be a reasonable doubt that coca, in common with tea and
coffee and other similar articles, has a refreshing, recuperative, and
sustaining effect upon human beings, and when well cultivated, well
cured, and well preserved, so as to reach its uses of good quality and in
good condition, it is at least equal to good tea, and available for
important therapeutic uses. Mr. Dowdeswell supposed that he used good
coca, but it is very easy to see that with any amount of care and pains
he may have been mistaken in this. Had he but used the same parcel of
coca that Sir Robert Christison did, the results of the two observers
would be absolutely incomprehensible; and the results, in the absence of
any testimony on that point, simply prove that the two observers were
using a different article, though under the same name, and possibly with
the same care in selection. On Sir Robert Christison's side of the
question there are many competent observers whose testimony is spread
over many years; while on Mr. Dowdeswell's side there are fewer
observers. But there has been no observer on either side whose researches
have been anything like so thorough, so extended, or so accurate as those
of Mr. Dowdeswell. Indeed, no other account has been met with wherein the
modern methods of precision have been applied to the question at all; the
other testimony being all rather loose and indefinite, often at second or
third hands, or from the narratives of more or less enthusiastic
travelers. But if Mr. Dowdeswell's results be accepted as being
conclusive, the annual consumption of 40,000,000 pounds of coca at a cost
of 10,000,000 dollars promotes this substance to take rank among the
large economic blunders of the age.[9]

[Footnote 9: An excellent summing up of the character and history of
coca, from which some of the writer's information has been obtained, will
be found in "Medicinal Plants," by Bentley and Trimen, vol. i., article
40.]

The testimony in regard to the effects of tea, coffee, Paraguay tea,
Guarana and Kola nuts, is all of a similar character to that upon coca.
Each of these substances seems to have come into use independently, in
widely separated countries, to produce the same effects, namely, to
refresh, renew, or sustain the physical and mental organism, and it was a
curious surprise to find, after they had all been thus long used, that
although each came from a different natural order of plants, the same
active principle--namely, caffeine--could be extracted in different
proportions from all. It is now still more curious, however, to find that
for centuries another plant, namely coca, yielding a different principle,
has been in use for similar purposes, the effects of which differ as
little from those of tea, coffee, etc., as these do among themselves. Yet
cocaine is chemically very different from caffeine, simply producing a
similar physiological effect in much smaller doses. All these substances
in their natural condition seem to be identical in their general
physiological effect, but idiosyncrasy, or different individual
impressibility or sensitiveness, causes a different action, as well in
quality as in degree from the different substances, upon some persons.

In order to throw a little additional light on the comparative activity
of the principal individuals of this group of substances, the following
trials were made. It is generally admitted, and is probably true, that
the same power in these agents which refreshes, recuperates, and sustains
in the condition which needs or requires such effects also counteracts
the tendency to sleep, or produces wakefulness when a tendency to sleep
exists; and, therefore, if a tendency or disposition to sleep could be
prevented by these agents, this tendency might be used as a measure of
their effects when used in varying quantities, and thus measure the
agents against each other for dose or quantitative effect. In this way
the proposition is to first measure coca against tea, then coffee against
guarana, and finally to compare the four agents, using pure caffeine as a
kind of standard to measure by.

An opportunity for such trials occurred in a healthy individual
sixty-five years old, not habituated to the use of either tea, coffee,
tobacco, or any other narcotic substances, of good physical condition and
regular habits, and not very susceptible or sensitive to the action of
nervines or so-called anti-spasmodics. Quantities of preparations of
valerian, asafoetida, compound spirit of ether, etc., which would yield a
prompt effect upon many individuals seem to have little or no effect upon
him, nor do moderate quantities of wines or spirits stimulate him. That
is to say, he has not a very impressible nervous organization, is not
imaginative, nor very liable to accept results on insufficient or partial
evidence.

Fully occupied with work, both physical and mental in due proportion, for
more than ten hours every secular day, when evening comes he finds
himself unable to read long on account of a drowsiness supposed to be of
a purely physiological character. With a full breakfast at about 7:30, a
full dinner at about 2:30, and a light evening meal about 7, and no
stimulants, or tea, or coffee at any time, he finds, as a matter of not
invariable but general habit, that by half past 8 drowsiness becomes so
dominant that it becomes almost impossible, and generally impracticable,
to avoid falling asleep in his chair while attempting to read, even
though ordinary conversation be carried on around him.

The first trial to combat or prevent this drowsiness was made with
caffeine. The first specimen used was a very beautiful article made by
Merck of Darmstadt, and after that by pure specimens made for the
purpose, the two kinds being found identical in effect.

Commencing with a one grain dose at about 6:30 P.M., on alternate
evenings, leaving the intermediate evenings in order to be sure that the
nightly tendency still persisted, and increasing by half a grain each
alternate evening, no very definite effect was perceived, until the dose
reached 21/2 grains, and this dose simply rendered the tendency to sleep
resistible by effort. After an interval of three evenings, with the
tendency to sleep recurring with somewhat varying force each evening, a
dose of 3 grains was taken, the maximum single dose of the German
Pharmacopoeia. This gave a comfortable evening of restedness, without
sleep or any very strong tendency to it until ten o'clock. Without
anything to counteract sleep, the rule was to read with difficulty by
nine, without much comprehension by quarter past nine, and either be
asleep or go to bed by half past nine. The 3 grain dose of caffeine
repeatedly obviated all this discomfort up to ten o'clock, but did not
prevent the habitual, prompt, and sound sleep, from the time of going to
bed till morning.

This was the model established, upon and by which to measure all the
other agents, and they were never taken nearer than on alternate
evenings, with occasional longer intervals, especially when the final
doses of record were to be taken.

The next agent tried in precisely this same way was coca; and knowing
that the quality of that which was attainable was very low, the
commencing dose of the leaf in substance was 2 drachms, or about 8
grammes. This gave no very definite effect, but 21/2 drachms did give a
definite effect, and a subsequent dose of 21/2 fluid drachms of a well made
fluid extract of coca gave about the same effect as 21/2 grains of
caffeine. Three fluid drachms of the fluid extract were about equivalent
to 3 grains of caffeine.

Both the coca used and the fluid extract were then assayed by the modern
methods, for the proportion of the alkaloid they contained.

The only assays of coca that could be found conveniently were those of
Dr. Albert Niemann, of Goslar, given in the _American Journal of
Pharmacy_, vol. xxxiii., p. 222, who obtained 0.25 per cent.; and of
Prof. Jno. M. Maisch, in the same volume of the same journal, p. 496, who
obtained 4 grains of alkaloid from 1,500 grains of coca, which is also
about a quarter of one per cent. These assays were, however, very old,
and made by the old process. The process used by the writer was the more
modern one of Dragendorff slightly modified. It was as follows:

Thirty grammes of powdered coca, thoroughly mixed in a mortar with 8
grammes of caustic magnesia, were stirred into 200 c.c. of boiling water,
and the mixture boiled for ten minutes. The liquid was filtered off, and
the residue percolated with about 60 c.c. of water. It was then again
stirred into 150 c.c. of boiling water, and was again boiled and
percolated until apparently thoroughly exhausted. The total liquid,
amounting to more than 600 c.c., was evaporated on a water-bath,
commencing with the weaker portions, so that the stronger ones might be
exposed to the heat for the shortest time, until reduced to about 20 c.c.
This liquid extract was transferred to a flask, and vigorously shaken
with 50 c.c. of strong ether. The ether was poured off, as closely as
practicable, into a tared capsule, where it was allowed to evaporate
spontaneously. A second and third portion of ether, each of 50 c.c., were
used in the same way, and the whole evaporated to dryness in the capsule.
A scanty, greenish, oily residue was left in the capsule, in which there
was no appearance of a crystallized alkaloid. The capsule and contents
were then weighed and the weight noted. The oily residue 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, together with a few particulars as to the
esculent properties of the tubers, may be worth recording, as I believe
several gardeners, among them being the Messrs. Sutton, have obtained
tubers of the Ullucus from Kew with a view to giving it a trial. The two
Caracas tubers mentioned above were as large as hens' eggs, rather
longer, and somewhat flattened; the skin was red, as in some potatoes.
These, when placed in heat, rapidly developed shoots, which were removed
as soon as they were strong enough to form cuttings; in this way about a
hundred sturdy young plants were obtained and made ready for planting out
of doors in June. They were planted in a light, sandy, well manured soil
in a position exposed to full sunshine. Here they grew quickly, forming
by the middle of August tufts of shoots and leaves one foot across. They
were earthed up as for potatoes, and the strongest shoots were pegged
down and partly covered with soil, though the latter proved unnecessary.
At this time there were no tubers nor any signs of them. On again
examining the plants in September (about the middle), we were surprised
to find no tubers had yet been formed. The plants were now very strong,
and it was therefore concluded that instead of forming tubers the
strength of the plants had "run to leaves." We gave them up, no further
notice being taken of them till the frost came, when on perceiving that a
frost of four or five degrees did not injure the foliage, we again
examined the plants, and found an abundant crop of tubers just below the
surface of the soil, and varying in size from that of peas to pigeons'
eggs. The plants were left till the haulms had been destroyed by cold,
after which the tubers were gathered. On cooking some of the larger ones
by boiling for half an hour, we found them still rather hard, and with a
flavor of potatoes, almost concealed under a strong earthy taste, quite
disagreeable and soap-like. Considering how short a time these tubers had
had to grow in it is not improbable that their hardness and disagreeable
taste were owing to their being unripe; no doubt young, green potatoes
(these Ullucus tubers were partly green) would be quite as nauseous as
these were.

[Illustration: MELLOCO TUBERS.]

We are told that the Ullucus is extensively cultivated in Peru and
Bolivia, in the elevated regions where the common potato also thrives,
and with which the Ullucus is equally popular as a tuber-yielding plant.
In the _Gardeners' Chronicle_ for 1848, p. 862, Mr. J.B. Pentland stated
that the Ullucus "is planted in July or August, the seed employed being
generally the smaller tubers, unfit for food, and is gathered in during
the last week of April. These two periods of the year are the spring and
autumn in the southern hemisphere. The mode of cultivation is in drills,
into which the root is dropped, with a little manure. The climate, even
during the summer season, is severe, scarcely a night passing over
without the streams being frozen over, the sky being in general cloudless
at all periods of the year except during the rainy season (December to
March). Mean temperature about 49 deg.." This information seems to support
the view formed of this plant from its behavior at Kew last year, namely,
that the tubers are formed on the approach of cold weather, and that, so
long as the weather is warm and bright, leaves only are developed. Plants
grown in houses where the temperature has not been allowed to fall below
50 deg. in winter did not form any tubers, although they were in good health.
We found no tubers on the plants grown out of doors till some time after
the return of cold, wet weather. It seems likely that this plant does not
develop tubers unless its existence is threatened by cold; at all events,
such a conclusion seems reasonable from the above statements.

Possibly a wet and rather cold autumn would be favorable to this plant
and the production of its tubers--such a season, for instance, as would
be most unfavorable for the common potato. It would be worth while
testing the Ullucus for low and cold situations where the potato would
not thrive. There is not much probability of the former ever proving a
substitute for or even a rival to the potato, at least in this country;
but there is room for another good esculent, and the Ullucus is prolific
enough, hardy enough, and, we suppose, when properly grown, palatable
enough to be worthy a trial. In the _Gardeners' Chronicle_ for 1848, p.
828, will be found a most interesting detailed account of experiments
made with this plant in France by M. Louis Vilmorin.--_W. Waston, Kew;
The Gardeners' Chronicle_.

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