Another verdict may now seem to have been hardly possible. The
accusation was built up on the jealousy of neighbours, on chance
circumstances, on testimonies founded on petty spite. But, combined with
the medico-legal evidence, the weight of circumstance might easily have
hoisted the accused in the balance.
It will be seen, then, how much on foot the case of the Veuve Lacoste
was with that of the Veuve Boursier, twenty years before.
It is on the experience of cases such as these two that the technique
of investigation into arsenical poison has been evolved. In the case of
Veuve Boursier you find M. Orfila discovering oxide of arsenic where M.
Barruel saw only grains of fat. Four years previous to the case of the
Veuve Lacoste that same Orfila came into the trial of Mme Lafarge with
the first use in medical jurisprudence of the Marsh test, and based
on the experiment a cocksure opinion which had much to do with the
condemnation of that unfortunate woman. In the Lacoste trial you find
the Parisian experts giving an opinion of no greater value than that
of Orfila's in the Lafarge case, but find also an element of doubt
introduced by the country practitioner, with his common sense on the
then moot question of the accumulation, the absorption, and elimination
of the drug.
Nowadays we are quite certain that our experts in medical jurisprudence
know all there is to know about arsenical poisoning. What are the
chances, however, in spite of our apparently well-founded faith, that
some bristle-headed local chemist with a fighting chin will not
spring up at an arsenic-poisoning trial and, with new facts about the
substance, blow to pieces the cocksure evidence of the leading expert
in pathology? It may seem impossible that such a thing can ever happen
again--a mistake regarding the action of arsenic on the human body. But
when we discover it becoming a commonplace of science that one human may
be poisoned by an everyday substance which thousands of his fellows
eat with enjoyment as well as impunity--a substance, for instance, as
everyday as porridge--who will dare say even now that the last word has
been said and written of arsenic?
But that, as the late George Moore so doted on saying, is quelconque. M.
Orfila, sure about the grocer of the Rue de la Paix, was defeated by M.
Barruel. M. Orfila, sure about the death of Charles Lafarge, is declared
by to-day's experts in criminal jurisprudence and pathology to have been
talking through his hat. According to the present experts, says "Philip
Curtin," Lafarge was not poisoned at all, but died a natural death.
Because of M. Devergie it was for the Veuve Lacoste as much 'touch and
go' as it was for the Veuve Boursier twenty years before. Well might
Marie-Fortunee Lafarge, hearing in prison of the verdict in the Lacoste
trial, say, "Ma condamnation a sauve Madame Lacoste!"
In all this there's a moral lesson somewhere, but I'm blessed if I can
put my finger on it.