The Washington union. [volume] (City of Washington [D.C.]) 1857-1859, 1859-03-19
THE EFFECTS or ARSENIC.

The proceedings of the Boston Society OF Natural His.
tory are full of interest. We copy the following from the
report of the Boston Traveller
Mr.. i. III. Storer read a paper ON the power possessed
by the larye of various common flies of consuming, with
out apparent injury to themselves, the flesh of animals
which have died from the effects of arsenic. last June
he found several larvae upon the liver of a subject In
whose stomach he had previously detected the presence
of arsenic this liver was found on analysis to be satu
rated with arsenic. In order to determine IL the larys
were actually nourished by such poisonous flesh, the
bodies Of several rats, poisoned to death by arsenious
acid, were exposed to the flies in AZ hours they were
completely fly blown, and in the course of a week all the
flesh had been consumed by the Larvae after this they
were changed into chrysalids.
These chrysalids on analysis yielded metallic arsenic.
1t might be supposed that the arsenic, thus obtained, had
been attracted mechanically to the external surface of the
Larvae, and had not been swallowed, especially as the
bones denuded OF flesh were covered with a white powder
resembling arsenic however this may be, the Larvae must
either instinctivcly reject the poison, or ii is excreted by
them after ingestion. A number OF these chrysalids were
kept in order to ascertain if they would undergo meta
%morphosis, and, If SO, whether the perfect insects would
be healthy and vigorous--some were kept for two months,
at the end of which time they were accidentally lost,
without undergoing any change, remaining, however in a
perfect state Of preservation and full of pulp a number
of small flies, apparently not iehneumous, which gained
access to them, died almost Immediately, as was sup.
posed from having fed upon them the empty shells Of
other ~chrysalids found about the room showed that some
had been metamorphosed, as none but the arsenicalIy-fe
Larvae had been admitted to the apartment.
Experiments made TO determine how large a quantity
of arsenic might be contained in flesh without rendering
1t unfit for the food of these larvn were not very salts
factory, from the hardening of the tissue by solutions of
this substance, preventing the deposition of the eggs
eggs developed in such tissue bring forth living worms,
which in his experiments died in 6 or 8 hours. The
adult flies persisted in great numbers while depositing
the eggs upon the poisoned flesh. Jaeger quoted by
Orfla Toxicologie l, 800 alludes to the fact that larvae
of flies live o little longer than the perfect insects, when
arseneous acid is introduced into the digestive organs or
applied to their external soft parts. Under favorable
moist conditions, the larvae lived 3 or 4 days, and were
evidently nearly ready to pass into the chrysalid state.
Experiments with arsenic acid, used, however, in too con
ccntrated a state, also showed that there is q limit to the
amount of arsenic which these larvae can support.
He was inclined to believe that they can eat with i'm
punity any flesh into which arsenic has been carried by
vital processes, from the fact of their being found upon
the a~rsenicated liver, an organ capable Of absorbing a
very large quantity of this poison; anatomical prepare
tions, injected thoroughly with arsenic acid, have been
found completely riddled and alive with Larvae.
This matter is important to chemists occupied in ju-
dicial Investigations, who should not infer that a fly
blown organ can contain no arsenic though, if flies die
almost Immediately after a~lighting on a suspected sub
stance, arsenic is probably present, and should be special
ly sought for. These facts are also interesting, as show
ing the great differences which exist in animals in
their several conditions OF metamorphosis and as indi-
eating the caution with which the results of experiments
on one species should be received as applying to other
species.
The popular belief that a body, dead from the effects
Of arsenic, must of necessity be preserved from decay for
an indefinite length of time, is unquestionably an error.
In many cases of murder or suicide, where a great amount
of the poison is administered, portions of, or even the
whole, body may be preserved for a long time but the
few grains, which it is admitted are enough 10 cause
death, cannot preserve from decay so large a mas as the
human body that n small, though fatal, dose will not
prevent decomposition, is well known to all who have
ever had poisoned rats die in the walls of their houses.