Notes of medico-legal cases : with comments / by John Crawford.

  • Crawford, John (fl. 1850)
Date:
1856
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Licence: Public Domain Mark

Credit: Notes of medico-legal cases : with comments / by John Crawford. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    shops, or manufactured for commercial purposes, it is seldom a pure sulphide of arsenic. The same remark applies to the orpi- ment of commerce, although that term is often applied, even by scientific writers, to the yellow or trisulphide of arsenic. 1 he common orpiment of the shops is, according to Dr. Christisony a mixture of arsenious acid and sulphide of arsenic; while what is sold as kiny’s-yellow is a compound of sulphide of arsenic, caustic lime 1 and free sulphur.f This statement, if generally applicable, is of great importance, as enabling us to estimate the comparative poisonous properties of the pure and the impure sulphides. lie former are generally reckoned very much less active poisons than arsenious acid—an opinion which is borne out by the tact, that the sulnhides are more difficult of solution in water, especially when the fluid is warm and acid—conditions usually obtaining m the stomach. If this view be correct, it would follow from the above statement of Dr. Christison, that the orpiment ot commerce, from the admixture of arsenious acid, would be more active as a poism than the pure sulphides, and the article, sold as king s- yellow from the lime and sulphur which it contains, considerably le^s active But from the inquiries 1 have been led to make, i doubt whether the above distinctions apply to these substances as met with in the shops in this part of the country Perhaps they apply to orpiment and king’s-yellow when carefully prepared as pigments. Among the fine artists’ colours made in London, both orpiment and king’s-yellow are to be found, the colour ot the former having a decided orange tint, when compared with the lemon yellow of tire latter. But as they are sold in ordinary colour shops, no such distinction can be traced. Indeed, the two terms seem generally to be considered as synonymous by the dealers. Hence, in purchasing, whether we ask tor orpiment 01 kinff’s-vellow, we get the same substance—a sulphide of aisenie, often probably containing a certain proportion of arsenious acid besides other accidental ingredients. Nay, as the arsenious acid is very much cheaper than sulphide of arsenic, there ,s an induce- ment to colour the acid by some other substance, a process which would not at all interfere with its efficacy as a poison for vermin, although it would destroy its utility as a pigment. I obtained a sample of what was sold as king s-ye ow m the case I have narrated, and which had been supplied to the tetai er by a wholesale drug house. Its colour was very peculiar, being mke of a brick redffian a sulphur yellow. Dr. Penny was kind enough to make an analysis of this sample, and found that * Christison on Poisons, fourth edition, p. 286. . , M -t- t o cur_ t In the third volume of the Transactions ot the Prov.ncial M die t and . gicnl Association, is an excellent account, by Dr. Symonds of B..-toot a et c !f poisoning bv orpiment, which resulted in the cnnvictmn and exec,™> « » «- 1_a female The substance which had been sold as oipiment, it, in^mce is described as being more of a red than a yellow clour, and on InaLis l'y M- Herapaffi was found to contain 79 per cent, of arsemons acid.