[TOXICOLOGICAL MEMORANDA.]
INTRODUCTION.
[CHAPTER I.]
DEFINITION AND MODE OF ACTION OF POISONS.
Toxicology (τοξικὸν poison, and λόγος discourse,) is that branch of medical science which treats of the nature, properties, and effects of poisons.
It appears scarcely possible to give any definition of a poison which will bear a critical examination; insomuch that some have preferred to deal with the evil effects of any substance, that is poisoning, rather than with the substance itself, the so-called poison. Most medicines are poisonous in improper doses; and even common salt (chloride of sodium) has caused death.[A] Dr. Guy defines a poison to be any substance which, when applied to the body externally, or in any way introduced into the system, without acting mechanically, but by its own inherent qualities, is capable of destroying life. A cherrystone may cause death by becoming arrested in the vermiform appendix, and thus producing peritonitis; boiling water may cause death also; but neither are poisons: the one acting mechanically, the other by its heat merely.
Any substance which can injure the health or destroy life is regarded as a poison, if given with the intent to do mischief. The words of the statute (1 Vict. c. 85, sec. 2) are—“Whoever shall administer, or cause to be taken by any person, any poison, or other destructive thing, with intent to commit murder, shall be guilty of felony, and being convicted thereof shall suffer death.” Sometimes poisons are administered, not for the purpose of destroying life, but of causing some slight injury or annoyance. An Act passed in March, 1860 (23 Vict. c. 8), provides for the punishment of a guilty person under these circumstances. If life be endangered, or “grievous bodily harm” result, the administrator may be found guilty of felony, and sentenced to penal servitude for a term not exceeding ten years. If the intent be only to “injure, aggrieve, or annoy,” the crime is reduced to a misdemeanor, punishable with an imprisonment for not more than three years.
In accordance with the Pharmacy Act certain substances have been defined as poisons within the meaning of the Act, so as to put some restriction on their sale to the public.