relied on. When sulphuretted hydrogen is passed through solutions of
these metallic substances colored precipitates are thrown down, which
at one time were thought to be absolute proof of the existence of the
poison in the original solution. But in the celebrated Donnal case,
tried at Falmouth, England, in 1817, Dr. Neale saved the accused by
showing that a decoction of onions, of which the deceased had eaten a
short time before death, yielded similar precipitates to those relied
upon by the prosecution as establishing the presence of arsenic in
the stomach. In regard to tartar emetic, Dr. Taylor, in his work on
medical jurisprudence, says: "Antimony in the metallic state is so
easily procured from a small quantity of material that on no account
should this be omitted. A reliance on a small quantity of a colored
precipitate would be most unsatisfactory as chemical evidence." In
defiance of all the authorities the prosecution, on the trial of Mrs.
Wharton for the murder of General Ketchum, rested its proof of poison
upon these color tests and their sequences. The defence, however,
found that the counterparts of three out of the four so-called
characteristic reactions were readily performed with the substances
known to have been in the stomach of General Ketchum at the time of
his death.

Several cases of poisoning which have been tried recently in this
State and Maryland have attracted much attention, and I propose now
briefly to outline these, and show that the disgraceful scenes
which have taken place were not due to deficiencies of toxicological
science, but to the causes already spoken of.

First in time among these _causes célèbres_ was the Schoeppe case,
the facts of which may be briefly summed up as follows: Dr. Schoeppe,
a young German practicing medicine in Carlisle, Pennsylvania, became