us bites, food poisoning, cantharides.
1. Irritant { Vegetable--all strong purgatives, hellebores, savin,
{ yew, ergot, hemlock, laburnum, bryony, etc.

2. Neuronic.

(a) Somniferous--opium and its alkaloids.
(b) Deliriant--belladonna, hyoscyamus, stramonium, cannabis,
cocaine, cocculus, camphor, fungi.
(c) Inebriants--alcohol, ether, chloral, carbolic acid (weak),
benzol, aniline, nitro-glycerine.

3. Sedative or depressant.

(a) Neural--conium, lobelia, tobacco, physostigma.
(b) Cerebral--hydrocyanic acid.
(c) Cardiac--aconite, digitalis, colchicum, veratrum.

4. Excito-motory or convulsives--nux vomica, strychnine.

5. Vulnerants--powdered glass.

III. _Asphyxiants._

Poisonous and irrespirable gases.

IV.--EVIDENCE OF POISONING

It may be inferred that poison has been taken from consideration of the
following factors: Symptoms and post-mortem appearances, experiments on
animals, chemical analysis, and the conduct of suspected persons.

1. _Symptoms_ in poisoning usually come on suddenly, when the patient is
in good health, and soon after taking a meal, drink, or medicine. Many
diseases, however, come on suddenly, and in cases of slow poisoning the
invasion of the symptoms may be gradual.

2. _Post-Mortem Appearances._--These in many poisons and classes of
poisons are characteristic and unmistakable. The post-mortem appearances
peculiar to the various poisons will be described in due course.

3. _Experiments on Animals._--These may be of value, but are not always
conclusive.

4. _Chemical Analysis._--This is one of the most important forms of
evidence, as a demonstration of the actual presence of a poison in the
body carries immense weight. The poison may be discovered in the living
person by testing the urine, the blood abstracted by bleeding, or the
serum of a blister. In the dead body it may be found in the blood,
muscles, viscera--especially the liver--and secretions. Its discovery in
these cases must be taken as conclusive evidence of administration. If,
however, it be found only in substances rejected or voided from the
body, the evidence is not so conclusive, as it may be contended that the
poison was introduced into or formed in the material examined after its
rejection from the body, or if the quantity be very minute it will be
argued that it is not sufficient t