Post-mortem Appearances.—Those of powerful irritation. The mucous membrane of the whole alimentary canal, from the mouth to the rectum, has been found in a state of acute inflammation. The uterus, kidneys, and internal organs of generation share also in the general irritation, ulceration of the bladder having been met with in some cases. Portions of the wings and elytra are sometimes found adhering to the coats of the stomach.
Fatal Dose.—One ounce of the tincture has caused death in fourteen days. This is perhaps the smallest fatal dose on record. Six ounces have been stated to have produced no dangerous symptoms. The worthlessness of the preparation may account for this result.
Treatment.—Vomiting should be promoted and warm mucilaginous drinks given. If vomiting be absent, emetics should be administered. Oil should not be given, as it dissolves out the active principle. Opium may be given with advantage.
Chemical Analysis.—The contents of the stomach should be concentrated and then treated with chloroform, filtered, and the filtrate allowed to spontaneously evaporate. A portion of the residue should then be placed on the skin, and the presence or absence of vesication noticed. Examined under the microscope, portions of the wing-cases may be detected. No change of colour is produced in cantharidine by the action of sulphuric or nitric acid, thus distinguishing this substance from any of the vegetable alkaloids.
PUTREFACTIVE OR BACTERIAL
ALKALOIDS
The processes by which complex and highly organised substances are broken up into their primary elements are largely synthetical. The putrefactive processes brought about by the action of bacteria result in the formation of special products, some of which combine with certain mineral and vegetable acids to form definite chemical salts; in this respect they correspond with inorganic and organic bases. These products are called ptomaines, a name suggested by an Italian toxicologist, Selmi, and it is derived from the Greek word πτῶμα, a cadaver or corpse.
On account of their basic properties, resembling the vegetable alkaloids, they are called putrefactive or bacterial alkaloids. They have been called animal alkaloids, but some ptomaines may be produced by the action of bacteria upon vegetable proteids; so this term is not strictly applicable, and should be restricted to those basic bodies or “leucomaines” that result from metabolism of the tissues in the animal body.
The essential element of their basic nature is nitrogen, and in this they resemble the vegetable alkaloids. Some contain oxygen, like the fixed alkaloids, while others do not, like the volatile alkaloids nicotine and conine. The kind of ptomaine formed depends upon the nature of the bacterium, the material upon which, and the conditions under which, it grows; the amount of oxygen present; the temperature and the period of growth. All ptomaines are not necessarily poisonous. Albumin is the origin from which all alkaloids, vegetable or animal, are derived. The following is a list of the principal ptomaines:
Methylamine, CH₃NH₂.—Found in herring brine and decomposing fish—non-poisonous.
Dimethylamine, (CH₃)₂NH₂.—From putrefying gelatine, yeast, fish, and sausage—non-poisonous.