488

ELEMENTS OF MATERIA MEDICA.

In large doses, especially in very susceptible persons, it affects thenervous system, and causes fainting, anxiety, and cramps. Twenty-three and a half grains in one instance (■ Journ. de Chim. Med. i. 210)caused death in nine days. The most remarkable symptoms were,obstinate vomiting; mercurial ulceration of the mouth and abundantptyalism; contractions of the heart, which at first were very strong, butbecame successively slower and more feeble; the abdomen was yielding,and not tender, notwithstanding the constant tenesmus; suppression ofurine ; semi-erection of the penis, and ecchymosis of this organ, as wellas of the scrotum ; and, ultimately, convulsive movements.

Uses, (a.) Medicinal. —It has been employed as an antivenerealmedicine, and was first used as such by Brera (llichter, op. cit .) Parent(Journ. de Chim. Med. viii. 473) administered it as a substitute for thebichloride of mercury, over which it has several advantages. Thus,being more soluble, it ought to be more readily absorbed; it does notgive rise to epigastric pain; and, lastly, it is not so readily decomposed ;lor alkalies, several salts, and many solutions of organic matters, whichdecompose corrosive sublimate, have no effect on it. It may be appliedin the form of aqueous solution or ointment to venereal sores.

It has been employed in induration of the liver, in some chronic skindiseases, in obstinate headache, and in other maladies, as an anti-phlogistic.

(b.) Pharmaceutical. —Its principal use in this country is as a sourceof hydrocyanic acid ( vide p. 237) and of cyanogen gas.

Administration. —Internally it may be employed in doses of one-sixteenth of a grain gradually increased to one-hall' of a grain. It maybe administered in the form of pills (made with crumb of bread) oralcoholic solution. It will be frequently advisable to conjoin opium, toprevent nausea or vomiting. When used as a gargle or wash, we mayemploy ten grains to a pint of water. An ointment may be prepared often or twelve grains to an ounce ol lard.

Antidote. —I am unacquainted with any antidote for it. Albumendoes not decompose it. Perhaps ammonia might be found serviceable, todiminish the effect on the nervous system. Opium relieves the vomiting.Our principal object must be to remove the poison from the stomach,which is to be effected by the stomach-pump, emetics, tickling thethroat, &c.

Unguentum Hydrar'gyri Nitra'tis. — Oint’ment of Nitrate of

Mercury.

History. —-This ointment is sometimes termed citrine ointment (un-guentum citrimim). Another name for it is mercurial balsam.

Preparation. —It is prepared by dissolving mercury in nitric acidand adding the solution to some kind of fatty matter. The relativequantities of acid and metal employed, as well as the nature of the fattymatter used, are various in different formulae. The following are theproportions directed to be employed in the British and United States Pharmacopoeias .