A dispensatory, or commentary on the phgarmacopoeias of Great Britain.

  • Robert Christison
Date:
1848
Catalogue details

Licence: Public Domain Mark

Credit: A dispensatory, or commentary on the phgarmacopoeias of Great Britain. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

    98/1058 page 48
    London College limits the proportion of sulphate to two and a- half in the thousand. An excess above this limit indicates a very inferior article, and is most correctly ascertained by distil- ling the acid and weighing the residuum. But indeed the Col- lege has allowed the manufacturer too much latitude. For in three samples of sulphuric acid made by extensive manufacturers in Scotland, I have found only 0.62, 0.80, and 0.85 grain in one thousand grains. The sulphate of lead is always thrown down in a great measure by dilution with water, and is the cause of the muddiness which then arises. The nitrous acid is also partly separated by dilution; which might therefore be employed as a test for its detection. But a much more delicate test of its presence is a solution of protosulphate of iron or of common green vitriol; which, when poured gently over the impure acid in a tube, immediately acquires a deep red colour at the line of contact from peroxidation of the iron by the nitrous acid, and communicates the same tint to the whole fluid upon agitation. This test, however, is to be used only in the case of an acid represented to be quite pure ; because it is so delicate that the commercial acid will seldom resist it altogether. An important adulteration, not uncommon on the continent, but scarcely known in this country except for a short time a few years ago, when manufacturers were led to use pyritic sulphur for making sulphuric acid, is arsenic. This substance, the presence of which in English acid was indicated not long ago by Dr Bees, may be easily detected by diluting the acid and passing through it a stream of sulphuretted-hydrogen ; upon which a yellow sulphuret of arsenic is formed, as the London and Edinburgh Col- leges have stated. It is stated to exist in the form of arsenic acid, and is left entirely in the retort when the sulphuric acid is carefully distilled. Sulphuretted-hydrogen is said not to remove it entirely from sulphuric acid, but this may be effectually done by an alka- line sulphuret [Dupasquier]. The presence of water in the commercial acid beyond what enters essentially into its constitution as a hydrate, is indicated by the density being under 1845. Medicinal Properties.—Sulphuric acid is a powerful corrosive and irritant when concentrated or slightly diluted. It is consequently a most deadly poison. Its antidotes are chalk, magnesia, carbon- ate of magnesia, or the alkaline bicarbonates. The alkaline car- bonates are objectionable as being themselves corrosive. Advan- tage baa been taken of the corrosive action of sulphuric acid for effecting counter-irritation in sonic local diseases. An issue may be readily made with it in its concentrated state; but it is not an eligible article for the purpose, by reason of its liquidity. It is sometimes applied as a caustic to the akin of the eye-lid for curing inversion of the lid, and to the conjunctiva for curing eversion. When diluted with eight parte of lard, according to a formula in the Dublin Pharmacopoeia, it produce- redness or ulceration. An ointment of half that proportion was recommended by Dr Duncan. 3
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