Adulterations detected, or, Plain instructions for the discovery of frauds in food and medicine / by Arthur Hill Hassall.

  • Hassall, Arthur Hill, 1817-1894.
Date:
1861
Catalogue details

Licence: Public Domain Mark

Credit: Adulterations detected, or, Plain instructions for the discovery of frauds in food and medicine / by Arthur Hill Hassall. Source: Wellcome Collection.

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    woody fibre. This practice is as objectionable as the one we have already had occasion to comment on — namely, the use of the word traces to designate all the organic matter contained in water. In the present case, the actual quantity of woody fibre rarely amounts to one per cent., the tuber being mainly composed, as already pointed out, of cellular tissue. Jalap resin may be prepared in the following manner : — The resin, together with other extractive, is dissolved out by alcohol; to the alcoholic solution water is added, which precipitates the resin ; this is washed in warm water, and re-dissolved in alcohol; or the alcoholic solution may be at once decolourised by animal charcoal; the first method, however, is the best, as by it all the sugar, &c., which may be present, as well as most of the colouring matter, is got rid of. Jalap resin is characterised by the following properties: — It is soluble in alcohol; insoluble in water, ether, the fixed and volatile oils, including oil of turpentine; triturated with milk, it does not form an emulsion ; digested in a watch-glass with sulphuric acid, a crimson coloured solution is obtained, this being a very distinctive test. From scammony resin, it is distinguished by its not forming an emulsion with milk, and by its insolubility in oil of turpentine. It is said to be sometimes adulterated with guaiacum, which, unlike jalap resin, is soluble in ether ; and paper moistened with the alcoholic solution, exposed to the fumes of nitrous acid, turns blue. According to some observers, as Buchner, Herberger*, and Kay- serf, the so-called jalap resin is a compound body, and consists of two resins, the one soluble in ether, the other insoluble in that men- struum. In relation to these, we meet with the following particulars in the third edition of Pereira's Materia Medica: — '''Jalapin; ?'hodeoretin (from podeoc, rose-red, and prjrlvr], resin), H35 O This resin is insoluble in ether. Kayser obtained it by boiling purified jalap resin in ether, which took upthe jalapic acid and left the jalapin. According to Buchner and Herberger, it con- stitutes not quite nine tenths of jalap resin ; it is a transparent, colourless, odourless, and tasteless resin, very soluble in alcohol, but insoluble in water and in ether. It does not possess basic properties, as Buchner and Herberger supposed, but, on the contrary, possesses acid properties, reddens lit- mus, and is soluble in ammonia and acetic acid. If the salt which it forms with oxide of lead be decomposed by sulphuretted hydrogen, the resin is then found to have combined with the elements of water, and to have become converted into hydrorhodeoretin^ O^j. Jalapic acid, odorous principle of jalap (?), constitutes thirteen per cent, of jalap resin. It is a brown, soft, and greasy substance, which reacts as an acid, has the odour of jalap, and an acrid taste. * Ann. der Chem. u. Ph.irm., bd. li p. 81., 1844.; and Tharm. Journ. vol. iv, o. 327., 1845. t Pharm. Central-Blatt fur 1831, S.284.