Oxydum Hydrargyri Nitricum. D.
Nitric Oxyd of Mercury—Red Precipitate.
Qualities. Form, small scales of a bright red colour; Taste, acrid and corrosive. Chemical Composition. It is strictly speaking a sub-nitrate of mercury, for if it be boiled for a short time with six times its weight of water, the liquor when filtered yields a precipitate with ammonia. Solubility. It is slightly soluble in water, but extensively in nitric acid, without any effervescence. Uses. It is used only externally, as an escharotic. Officinal Prep. Unguent. Hydrargyri Nitrico-oxyd. L.E.D. Adulterations. Red Lead may be detected by digesting it in acetic acid, and adding sulphuret of ammonia, which will produce a dark-coloured precipitate: it should be totally volatilized by heat.
HYDRARGYRI OXYDUM CINEREUM. L.E.
Pulvis Hydrargyri Cinereus. D.
Grey Oxyd of Mercury.
Qualities. Form, an impalpable grey coloured powder, which becomes paler on exposure to air and light. Odour and taste, none. Chem. Composition. When properly prepared it is protoxide of mercury; but, as frequently found in the shops, it contains a mixture of the triple salt consisting of oxide of mercury, ammonia, and nitric acid. It is rarely used; although Dr. Saunders suggested it as a succedaneum for Plenck’s remedy, and Mr. Abernethy considers it preferable to the red Sulphuret for mercurial fumigation, on account of its not yielding any suffocating vapour. Officinal Prep. Unguent. Oxyd. Hydrarg. ciner. E.
HYDRARGYRI OXYDUM RUBRUM. L.
Oxydum Hydrargyri. D.
Red Oxyd of Mercury.