Manchester Memoirs, Vol. xlviii. (1904), No. IT. 



XVII. On the Electrolytic Methods for the Detection 

 and Approximate Estimation of Minute Quantities 

 of Arsenic in Beer, Malt, and Food Stuffs, Etc. 



By William Thomson, F.R.S.E., F.I.C. 



Read December i^th. Received April 12th, 1^04. 



On the 3rd of March of last year I read a paper 

 before this Society on the detection and approximate 

 estimation of arsenic by the Marsh-Berzelius method. I 

 now desire to place before you the results I have obtained 

 by the study of the electrolytic processes. 



During the sittings of the " Royal Commission 

 "on Arsenical Poisoning arising from the consumption 

 "^of beer, and other articles of food or drink," the 

 chairman, Lord Kelvin, suggested that an electrolytic 

 method of liberating hydrogen might be devised which 

 would remove the difficulty of providing arsenic-free zinc. 



I felt that his lordship (who was very strong on the 

 possibility of doing this) had not taken sufficiently into 

 consideration the chemical properties of the element with 

 which we had to deal, as I had previously tried an 

 electrolytic method and failed to get anything like the 

 required arsenical mirrors. 



A Committee was appointed by the Commissioners of 

 Inland Revenue, to suggest the best process and form of 

 apparatus for the detection and estimation of arsenic in 

 food and drink. The following were appointed members 

 of the Committee : — 



May 14th, igo4. 



