Solution of the Iodide of Arsenic and of Mercury. Liquor Arsenici et Hy-drargyri Hydriodatis (Ph. D.). Solution of the Iodo-Arsenite of Mercury. Commonly known as Donovan's Solution. So called after its inventor, Mr. Donovan, of Dublin. A combination of Iodine, Arsenic, and Mercury, the Iodine being combined with the metals in such proportion as to form the Teriodide of Arsenic (Asl3) and the Periodide of Mercury (Hgl). Mr. Donovan, however, considers that the Iodides are converted into Hydriodates. Each fl. drm. j. of the solution contains a quantity of Teriodide of Arsenic, equivalent to gr. 1/8 of Arsenious Acid, and of Iodide of Mercury, equivalent to gr. 1/4 of the Peroxide of Mercury, and gr. 3/4 of Iodine, converted into Hydriodic Acid.

Med. Prop. and Action. Alterative, in doses of fl. drm. ss. thrice daily. Mr. E. Wilson regards this dose as too large, in many cases giving rise to headache, nausea, and occasionally salivation; but these symptoms disappear when the medicine is discontinued. It is a very valuable preparation.

Dose, .ev. - exxx.

433. Therapeutic Uses

In obstinate Cutaneous Diseases, particularly in Psoriasis, Lepra, Pityriasis, Ephelis, Lupus, and Impetigo, the solution has been found highly successful by Mr. Donovan, Drs. Osbrey,§ Byron,|| Graves,¶ and others. Dr.

* Mat. Med. vol. i. p. 720. Med. Times and Gaz., March 12, 1864. On Diseases of the Skin, p. 281.

§ Dublin Journ , vol. xxi. p. 401, and vol. xviii. p. 97. || Ibid. vol. xxii. p. 57. ¶ Ibid. Sept. 1840.

Osbrey advises the following formula: -433 Therapeutic Uses 43 Liq. Are. et Hyd. Iod. gutt. lxxx., Aq. Dest. fviij., Syr. Zingib. fss., M. Dose, fj. every third hour. In Sycosis it has been found highly useful by Mr. E. "Wilson.*

In Urticaria or Nettlerash, Dr. Osbrey found the solution in doses of gutt. vj. thrice daily, productive of signal benefit.