APPENDIX
H
THIS rule of science is, to all appearance,
little known and respected. Recently the writer mentioned it to Major X.,
Indian Medical Service (retired), who promptly contradicted it by the assertion
that it was possible to prove things by negative evidences. As a case in point,
he cited the following: “If two fluids be mixed, and no effervescence ensue,
the conclusion may be drawn that the one fluid was not an acid, the other not
an alkali.” Without asking which was which, and how this was determined from
the negative result, the writer denied this. Shortly afterwards Major X. had
occasion to attempt a diagnosis of a sore in a student from Central India. By a
prominent surgeon it had been pronounced tubercular without a microscopical
examination, but one of my colleagues—University Lecturer on Proto-zoology and
Tropical Entomology—who was “not even a medical man,” suspected that it might
be “Oriental sore.” Major X.’s first microscopical examination of a scraping
turned out quite negative, but, in this instance, his scientific instincts
prevailing, he drew no conclusion, but resolved to examine further scrapings !
The rule of science, which says that “negative results never prove anything at
all in science,” is not laid down by me, or even on the authority of my departed
friend, the late Professor D. J. Cunningham, Head of the Department of Anatomy,
and Dean of the Medical Faculty of the University of Edinburgh. It may be
found elsewhere. Thus, a small book was published recently by Professor
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