Red Oxide of Mercury. HgO. Hydrargyri Nitrico-Oxidum. Nitric Oxide of

* Dublin Med. and Phys. Essays, vol. i. p. 307.

Note in Watson's Lectures, vol. ii. p. 840.

Lectures, vol. i. p. 194.

Mercury (Pharm. Lond.), called also the Binoxide and Peroxide of Mercury and Red Precipitate, one of the most poisonous preparations of Mercury.

Med. Prop. and Action. Stimulant and escharotic It is never given internally, but is extensively used externally, in the form of ointment. This, applied to extensive ulcerated surfaces, occasionally causes ptyalism. As an escharotic. it is occasionally applied alone, or mixed with sugar, to Specks in the Cornea, over Excrescences, Chancres, and Fungous Ulcers, (oarrod.*)

Offic. Prep. Unguentum Hydrargyri Oxidi Rubri (Finely powdered Red Oxide of Mercury grs. lxiv.; Simple Ointment oz. j.). Known as Red Precipitate Ointment.

1486. Therapeutic Uses

In Indolent Syphilitic Ulcerations, the Red Precipitate ointment is an excellent dressing, stimulating the surface, improving the quality of the discharge, and apparently hastening the healing process. It should not be applied to too large a surface at once, or the salt may become absorbed into the system, and induce salivation. A case of this description happened in my practice. To Flat Ulcers of the Rectum which exist just within the anus, Mr. Coulson advises the use of the following ointment: -1486 Therapeutic Uses 135 Hyd. Nit. Oxid. 3j., Ung. 3j., M. The bowels to be kept open.

1487. In The Ulcerations Of Rupia, The Ointment Has Often An Excellent Effect

The scabs should be first loosened and removed by soft emollient poultices, and the ulcers then dressed with the ointment spread on lint.

1488. In Frambsia or Yaws, temporary advantage is said to result from the local application of the Red Precipitate ointment; but the ulcers relapse into their former indolent state when the remedy is discontinued. It is of very doubtful utility.

1489. In Ophthalmia Tarsi, Chronic Conjunctivitis, and in some Chronic Affections of the Eye, a small portion of the ointment smeared over the edges of the eyelids at bedtime is attended with great benefit. In Purulent Ophthalmia, according to Dr. De Conde, it is often sufficient of itself to arrest the disease when employed early. He uses an ointment composed of four parts of Red Precipitate to fifteen of Lard and fifteen of Linseed Oil. He regards it as the best remedy in the Ophthalmia of New-born Infants.

1490. In Favus, Mr

E. Wilson speaks favourably of the ointment (ante) diluted with an equal weight of simple cerate.

1491. In Otorrha After Scarlet Fever, M

Trousseau § strongly advises an application composed of twenty-five parts of the Red Oxide, five of Almond Oil, and five of Lard. The external meatus is first washed out, and well dried, and the above introduced twice daily. Care should be taken to keep the tissues moist in the intervals with Olive Oil.

* Ess. Mat. Med., p. 91. Lancet, Aug. 17, 1861. Ann. d'Oeulistique, 1858, vol. xl

§ Journal de Med. et de Chir., Oct. 1850.