Any chemical substance that, when introduced
into or applied to the body, is capable of
injuring health or destroying life. The liver
is the organ that removes some poisons from
the blood. The majority of poisons may be
divided into corrosives, for example
sulphuric, nitric, and hydrochloric acids,
caustic soda, and mercuric chloride, which
burn and destroy the parts with which they
come into contact; irritants, such as
arsenic, copper sulphate, zinc chloride,
silver nitrate, and green vitriol (iron
sulphate), which have an irritating effect on
the stomach and bowels; narcotics, for
example opium, prussic acid, potassium
cyanide, chloroform, and carbon monoxide,
which affect the brainstem and spinal cord,
inducing a stupor; and narcotico-irritants,
which cause intense irritations and finally
act as narcotics, for example, carbolic acid,
foxglove, henbane, deadly nightshade
(belladonna), tobacco, and many other
substances of plant origin. In noncorrosive
poisoning every effort is made to remove the
poison from the system as soon as possible,
usually by induced vomiting. For some
corrosive and irritant poisons there are
chemical antidotes, but for recently
developed poisons in a new category (for
example, the weedkiller paraquat) that
produce proliferative changes in the system,
there is no antidote. In most countries the
sale of poison to individuals is carefully
controlled by law and, in general, only
qualified and registered pharmacists and
medical practitioners may dispense them.
However, industrial and agricultural poisons
are dumped into rivers and seas and on land,
entering the food chain. In noncorrosive
poisoning every effort is made to remove the
poison from the system as soon as possible -
usually by vomiting induced by an emetic. For
some corrosive and irritant poisons there are
chemical antidotes, but for recently
developed poisons (for example, the herbicide
paraquat) that produce proliferative changes
in the system, there is no antidote. Drugs
(legal and illegal), including nicotine and
alcohol, are toxins to the human body. In
most countries the sale of poison, as such,
is carefully controlled by law and, in
general, only qualified and registered
pharmacists and medical practitioners may
dispense them, however, industrial and
agricultural poisons are dumped into our
waters and onto our lands, entering the food
chain, and poisoning us and our planet.