﻿Manchester Memoirs, Vol. xlix. (1904), No. 1. 



I. On the Presence of Arsenic in the Body and its 

 Secretion by the Kidney. 



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



Read April 26th, 1904. Received July 26th, 1904. 



At a recent meeting of the Society of Chemical 

 Industry Mr. E. T. Battenshaw told me that arsenic 

 existed in Urine in comparatively large quantities. 



I made some experiments and satisfied myself that 

 the kidney secretion of people living in Manchester 

 certainly did contain arsenic, and I have extended the 

 research to find, if possible, the source of the contamina- 

 tion, having got rid of the difficulty of being certain 

 that every particle of the zinc employed in the Marsh- 

 Berzelius apparatus was free from arsenic by employing 

 the electrolytic method devised by me {Memoirs and 

 Proceedings of The Manchester Literary and Philosophical 

 Society, Vol 48, Part III. (Session 1903-1904)) which gives 

 special value to the results because one can be sure that 

 any minute quantities of arsenic found are really con- 

 tained in the substances examined and do not come from 

 the reagents. 



The estimations of arsenic in urine were made by 

 taking 50 cubic centimetres of the sample and adding to it 

 a mixture of 5 c.c. of strong sulphuric acid and 10 c.c. of 

 nitric acid both purified and arsenic-free ; these were 

 boiled down in a Jena glass flask* of 200 c.c. capacity till 

 the liquid began to darken, when a few c.c. more of nitric 

 were added, this being repeated until the liquid was colour- 

 less, when the whole was heated till white fumes of 



* These flasks were previously tested by boiling in them pure strong 

 sulphuric and nitric acids, and finding that the remaining sulphuric acid was 

 free from any trace of arsenic when submitted to the electrolytic test. 



October jth, Z904. 



