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. Poisons may be introduced into the body in various ways and in various forms. Thus they may be administered by the mouth or by the rectum, and they may be given in the form of solids, liquids, or gases, uncombined, or mixed with various matters. Some agents are more readily absorbed than others; whilst some textures permit of absorption taking place more quickly through them than other tissues. Thus, the most diffusible poisons prove most rapidly fatal, especially when introduced directly into the circulation by a wound in a vein, or when they are injected into the subcutaneous connective tissue. Their action is also speedy when applied either in a gaseous state to the pulmonary air-cells, or as a fluid to that of the stomach or intestines. The serous membranes, too, possess an activity of absorption almost superior to that of the mucous membranes; while absorption through the skin is slow, on account of the cuticle. Poisons taken into the stomach when that viscus is empty, necessarily act much more speedily than when it is full. It is remarkable that the agents which most affect the nervous system do not appear to act at all when applied directly to the brain or trunks of nerves. There are also some poisons, as that of the viper, which, although most deadly when introduced into the blood through a wound, are harmless when swallowed. The effects of poisons may be considered as _local_ and _remote_.