ature of the body."

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 substan