SPECIFIC ANIMAL IRRITANTS.
CANTHARIDES (_Spanish Flies_).
This poison is well known, and is usually administered in the form of
powder or tincture. Of the former, twenty-four grains have destroyed
life; of the latter, one ounce. This poison has been employed as an
aphrodisiac and to induce abortion, by persons ignorant of its dangerous
effects. This is, perhaps, the most frequent cause of poisoning by
cantharides. Applied externally it has proved fatal, as in the case of a
girl affected with scabies, who anointed the whole of her body with
cantharides ointment in mistake for that of sulphur. She died in five
days, after suffering from the symptoms of poisoning by cantharides.
It produces an acrid taste, vomiting, purging, burning heat in the
stomach, pain in the loins, severe strangury, bloody urine, and
priapism. Then there is faintness with giddiness, the limbs become
rigid, and delirium with convulsions precede death. Sometimes the
matters ejected from the stomach or passed in the stools contain shining
golden or green particles, the remains of the wing cases of the beetles,
which constitute the drug, readily seen with a lens, or even with the
naked eye.
After death, marks of inflammation are found in the alimentary canal,
kidneys and bladder, and the genital organs.
_Tests._--The detection of Spanish flies, if taken solid, depends mainly
on the presence of the shining particles already alluded to, in the
stomach, or in the vomited matters. To make their nature certain,
however, an extract of the suspected materials should be prepared and
treated repeatedly with chloroform or ether. This fluid is to be allowed
to evaporate till only a few drops are left, which may be applied on
lint to some portion of the body where the skin is fine, as the fore
arm, the part being covered by a bit of isinglass plaster, or
goldbeaters' skin. The vesication produced is the test of the presence
of cantharides.
No antidote is known. Vomiting must be excited or encouraged; and
linseed tea, and gum water, or gruel copiously administered. The warm
bath will afford great relief. Oil must be avoided, on account of its
being a solvent of the active principle (cantharidine) of this poison.
IV.--NEUROTIC POISONS.