Mercury and mercurial compounds, applied in the form of an ointment, have an irritating local action on the skin.
Taken internally they have a strong toxic action, producing nausea, colic, and salivation.
They bring about a sudden fall in blood- pressure, paralysis of respiration, and sometimes serious cardiac disturbances.
The most rapid effect is produced by inhalation of mercury vapour.
In cases of mercurial poisoning the metal accumulates to the highest concentration in the liver.
Mercury vapours and compounds are also toxic to plants.
Owing to their toxic effect on bacteria, mercury compounds, especially mercuric chloride, are used as antiseptics. They are also used medicinally.