BLUE PILL, Pinta hydrargyri, is the most simple form in which mercury can be administered internally. It consists merely of lure parts of mercury rubbed up with three parts of conserve of roses, till globules of mercury can no longer be detected; to this is added powdered licorice-root, so that a pill of five grains contains one grain of mercury.
In cases of torpid condition of the liver or inflammation of that organ, B. P. is much used as a purgative, either alone or combined with some other drug, such as rhu barb. When it is given with the view of bringing the system under the influence of mercury (salivation, q.v.), small doses of opium should be added to counteract its purga tive tendency, and the state of the gums watched carefully from (lay to day, so tint the, first symptoms of salivation may be and the medicine omitted. As a the common dose of B. P. is one or two pills of five grains each, followed by a purga
tive draught. When the system is to be saturated with it, or salivated, one pill may be given morning and evening, or one every night combined with f of a grain of opium, repeated till the gums become sore. But the sensibility to the action of mercury varies with the individual; some may take large quantities before it exhibits its physiological symptoms, and on the other hand, three blue pills, one taken on three successive nights, have brought on a fatal salivation. When taking blue pills, all sudden changes of tem perature should be avoided; and, indeed, though they are found in every domestic medicine-chest, neither they nor any other form of mercury should be given without good cause and without the greatest caution.