Medicines, their uses and mode of administration : including a complete conspectus of the three British pharmacopoeias, an account of all the new remedies, and an appendix of formulae / by J. Moore Neligan.
- John Neligan
- Date:
- 1849
Licence: Public Domain Mark
Credit: Medicines, their uses and mode of administration : including a complete conspectus of the three British pharmacopoeias, an account of all the new remedies, and an appendix of formulae / by J. Moore Neligan. Source: Wellcome Collection.
Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)
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![Preparation.—Calomelas subi.imatum, D. Persulphate of mercury, 45 parts; purified mercury, 17 parts ; muriate of soda, dried, 10 parts; tritu- rate together in an earthen-ware mortar, the persulphate and the purified mercury, till the metallic globules shall have completely disappeared, then add the dried muriate of soda ; mix well, and in a suitable vessel, with a gradually increased heat, sublime into a receiver; reduce the sublimed mass to powder, and wash it with water, as long as the decanted liquor pre- cipitates with solution of caustic potash ; finally dry the sublimed calomel.' —Hvdrargyri chloridum, L. [mite, U. S.J Mercury, Ibiv.; sulphuric acid, lbiij.; chloride of sodium, Ibiss.; distilled water, a sufficiency. Boil ibij. of the mercury with the sulphuric acid in a proper vessel, until a biper- sulphate of mercury remains dry ; rub this when it is cold with Ibij- of mer- cury in an earthen mortar, that they may be perfectly mixed. Afterwards add the chloride of sodium, and rub them together until globules are no long- er visible; then sublime. Rub the sublimate to very fine powder, and wash ii carefully with boiling distilled water, [Till the washings afford no precipi- tate upon ihe addition of solution of Ammonia ; U. S.] and dry it.—Calo- melas, E. Mercury, gviij ; sulphuric acid, lgij. f'3iij.; nitric acid, fgss.; muriate of soda, §iij. ; mix the acids, add to them giv. of the mercury, and dissolve it with the aid of a moderate heat; raise the heat so as to obtain a dry salt. Triturate this with the muriate of soda and the rest of the mercu- ry, till the globules entirely disappear; heat the mixture by means of a sand bath in a proper subliming apparatus. Reduce the sublimate to fine pow. der; wash the powder with boiling distilled water until the water ceases to precipitate with solution of hydriodate of potash ; and then dry it.—Calome- las prjecipitatum, D. Purified mercury, 17 parts ; diluted nitric acid, 15 parts; pour the acid upon the mercury, put into a glass vessel, and as soon as the mixture ceases to effervesce, digest with a medium heat for 6 hours, frequently agitating ; then increase, the heat that the liquor may boil for a short time, pour off from the residual mercury, and mix the liquid immediately with a solution of 7 parts of muriate of soda in 400 parts of boiling water; wash the precipitated powder with warm distilled water, as long as the poured off liquor is affected by solution of caustic potash ; finally dry the powder. Physical Properties.—Calomel as obtained by sublimation, is sometimes in the form of a semitransparent, white, crystalline cake, the crystals being four-sided prisms; as usually met with, however, it is a heavy, snow-white, soft powder, inodorous and tasteless. Its sp. gr. is 65 (Graham). Chemical Properties.—Calomel is a subchloride of mercury, being composed of 1 eq. of chlorine, and 2 of mercury (Hg2 CI.). It is completely insoluble in cold or boiling distilled water, in alcohol, or in ether. It acquires a yellow tinge by exposure to the air, or by rubbing; exposed to heat it becomes yellow, and volatilizes at a heat below redness, if under pressure it fuses; with lime water it gives a blackish precipitate, sub-oxide of mercury. Adulterations.—Calomel sometimes contains corrosive sublimate, which may be detected by agitating with sulphuric ether, pouring off the clear liquid and evaporating, if any sublimate be present a crys- talline powder is left which becomes yellow with solution of caustic potash ; this adulteration I have repeatedly detected in calomel, my attention having been always first directed to it, by the irritation which it produced when administered to patients ; one patient to whom calomel thus adulterated was given in the form of powder, complained of a burning sensation in the back of the mouth and pharynx. The presence of any fixed white powder may be detected by applying a sufficient heat to sublime the calomel.](https://iiif.wellcomecollection.org/image/b21143602_0091.jp2/full/800%2C/0/default.jpg)
