First report of the Royal Commission appointed to inquire into arsenical poisoning [1900] from the consumption of beer and other articles of food or drink.

  • Great Britain. Royal Commission on Arsenical Poisoning
Date:
1901-1903
Catalogue details

Licence: In copyright

Credit: First report of the Royal Commission appointed to inquire into arsenical poisoning [1900] from the consumption of beer and other articles of food or drink. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    combustion of the fuel and that which remains behind in the ash, two methods of prehminary treatment have been described to us. The first consists of burning the fuel with lime or other base in Ling, 10451-76. order that all the arsenic present may be retained in the residue after -'/w-~w. combustion is comj)lete, and also of estimating the arsenic which remains when the fuel is burnt alone : the difference between the two estimations representing volatile arsenic. The application of this method to fuel was described to us by Mr. Ling, and its principle has been adopted by Dr. McGowan in testing for the Commission the series of samples from anthracite collieries to which reference is made Para. 94, below, below. Dr. McGowan found that in solutions obtained from the residues after combustion, the presence of iron interfered materially with estimations of arsenic by the Marsh-Berzelius test. In Appendix 23 he has given (along with Mr. R. B. Floris) a detailed account of the Appx. ss, p. 227. pi'ocedures adopted in order to eliminate this and other sources of error. The second method, more recently described in the report of the Appx. 2i,p. 210. Departmental Committee (Appendix 21), consists in burning the fuel in a current of oxygen, collecting the arsenic which is volatilised in an absorption apparatus containing dilute sulphuric acid ; and subse- quently estimating the volatile arsenic o1)tained in this solution, and also the arsenic left behind in the ash. For this purpose, the ash, after suitable treatment, is distilled with hydrocliloi'ic acid and the distillate is used for the Marsli-Berzelius or electrolytic test. Comparison of Mirrors oirrAiNED by the Electrolytic Method. 57. The method of evolving arseniuretted hydrogen by electrolysis, Appx. 2i,p. 20s. without the use of zinc and acid, has recently been carefully studied by the Departmental Committee, whose Report gives an account of the appai'atus designed in the Government Laboratory for the purpose, and which can be applied where^'er an electric current of sufhcient intensity is available. The Committee have found that when the current is suitably con- trolled and other precautions which they describe are taken, the evolution of arseniuretted hydrogen takes place with great uniformity, and the resulting mirrors, though similar and comparable to those obtained by the zinc and acid method which they also describe, have the advantage of being more definite and thus allow for greater exactness in estimation. 58. Moreover, in examining in this way a variety of substances connected with brewing, they have found that the nature of the material associated with the arsenic exercises no inhil^itory effect on the formation and evolution of arseniuretted hydrogen. They are satisfied that beer and worts may be added directly to the electrolytic apparatus without previous destruction of organic matter. 59. We understand that this method is now adopted at the Govern- ment Laboratory in preference to the Marsh-Berzelius test with the use of zinc and acid, and now that the results of the Ci;>mmittee's work' are in the hands of chemists, wide experience of the working of the electrolytic method which they recommend may soon be looked for. Other Quantitative Methods. GO. Our (vidence shows that some chemists prefer, or at least have t^- i^^'^'^^''ivS^J^^'^'' in the past preferred, to estimate small quantities of arsenic by other joneriTss-m' means than comparison of mirrors ; e.g., gravimetrically, ]jy using a large quantity of the substance and weighing sulphide of arsenic finally obtained from it; i y extracting the arsenic by means of copper gauze; by the Gutzeit test .; or by the Reinsch test with subsequent examina- tion and comparisoiA of sublimates. Delepine, 4928, 5208, Ui ,31-'i-Si).
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