n of the cause of death in cases
of poisoning always depends partly on the symptoms noted before death,
and partly on the appearances found after death. Regarding the former,
neither of us knew anything; hence our difficulties were greatly
increased. The object of the analyst is to obtain the substances which
he has to examine chemically in as pure a condition as possible, so
that there may be no doubt about the results of his tests; also, of
course, to separate active substances from those that are inert, all
being mixed together in the stomach and alimentary canal. Again, in
dealing with such fluids as the blood, or the tissues of the body,
their natural constituents must be got rid of before the foreign and
poisonous body can be reached. There is this difficulty further to
contend with: that some of the most poisonous of substances are of
unstable composition and are readily altered by chemical reagents; to
this group belong many vegetable and most animal poisons. These,
therefore, must be treated differently from the more stable inorganic
compounds. With an inorganic poison we may destroy all organic
materials mixed with it, trusting to find the poison still
recognisable after this process. Not so with an organic substance;
that must be separated by other than destructive means.

Through the whole evening we tested for the various groups of
poisons--corrosives, simple irritants, specific irritants and
neurotics. It was a long and scientific search.

Some of the tests with which I was not acquainted I watched with the
keenest interest, for, of all the medical men in London, Tatham was
the most up to date in such analyses.

At length, after much work with acids, filtration, and distillation,
we determined that a neurotic had been employed, and that its action
on the vasomotor system of the nerves was very similar, if not
identical, with nitrate of amyl.

Further than that, even Tatham, expert in such matters, could not
proceed. Hours of hard work resulted in that conclusion, and with it
we were compelled to be satisfied.

In due course the inquest was held at Shadwell, and with Ambler I
attended as a witness. The reporters, of course, expected a sensation;
but, on the contrary, our evidence went to show that, as the poisonous
substance was found in the "quartern" bottle on deceased's table,
death was in all probability due to suicide.

Some members of the jury took an opposite view. Then the letters we
had fou