The above are the chief mercurial preparations that are given internally. Certain *external applications require a few remarks. The plasters, ointments, and liniments are absorbed by the skin, and act in the same manner as mercurials taken internally.
White precipitate ointment is the universal remedy for the destruction of lice, and is a useful stimulating application in chronic skin-diseases. Ointment of nitrate of mercur y, popularly known from its yellow color as citriae,. or golden. ointment, is, when sufficiently diluted a most useful stimulating applic,ation in inflamtnation of the eyelids, in indolent -ulcers, etc.; and the ointment of nitric oxide of mercury is similar in its action. The pre cipitated suboxide that occurs in black wash, and its use as a local application, are described in the article LINIMENTS.
The toxicological relations of the mercurial compounds must be briefly glanced at. 'There are cases on record in which, probably from some peculiarity of constitution, '-ordinary and even small doses of the milder mercurials have caused death; thus, Chris tison mentions a case in which two grains of calomel destroyed life by severe salivation and by ulceration of the throat ; and shuilar cases in which small doses of gray powder, blue pill, and calomel have proved fatal are recorded by Taylor in his Medical Jllri8 prudence. The preparations employed for the purpose of poisoning are mainly corrosive
sublimate anti white and red precipitates, corrosive sublimate beim* used in at least four-fifths of the cases. The symptoms produced by a poisonous dose o'f this salt come on Immediately, there being during the act of swallowing an intense feeling of constriction, .and a burning heat in the throat, while a metallic taste is left in the mouth. Violent ;pain in the stomach and abdomen is felt in a few minutes, and vomiting of inucus and blood, and purging, follow. The pulse becOmes small, frequent, and irregular, the tongue white a.nd shriveled, the skin cold and clammy, the respiration difficult, and deaili is preceded by fainting or convulsions. Any dose exceeding two grains would -probably prove fatal to an adult, unless vomiting were induced, or the whites of eggs administered. Death commonly ensues in frotn one to five clays, but may take place in less than half an hour, or not for three weeks or more.