536 



First published in Nature, 134, 879 (1934). 



54. ELIMINATION OF WATER FROM 

 THE HUMAN BODY 



G. Hevesy, E. Hofer 



From the Institute for Physical Chemistry, University of Freiburg 



Shortly after the first application of radioactive isotopes as indicators, 

 the late H. J. G. Moseley and one of the present writers discussed the 

 prospect opened by the introduction of this method, when indulging 

 in a cup of tea at the Manchester Physics Laboratory. The latter then 

 expressed the wish that an indicator might be found which would allow 

 one to determine the fate of the individual water molecules contained 

 in the cup of tea consumed. Even a man of the vision and outlook of 

 the late H. J. G. Moseley considered this hope to be a highly Utopian 

 one. 



The recent work of Urey and his collaborators brought, however, 

 the above-mentioned wish within the range of realisation. Although 

 diplogen and hydrogen, unlike the atoms of radioactive isotopes, are 

 not practically inseparable by chemical means, yet if we add to a cup 

 of tea a slight amount of heavy water and then find, for example, one 

 per cent of the latter in the water which has left the body, we can assume 

 that about one per cent of the 'normal' water molecules taken in with 

 the cup of tea has shared the same fate. 



That heavy water present in high dilution in the organism behaves 

 like light water is borne out by the fact that the heavy water content 

 of urine and other excreta is the same as that of ordinary tap water, 

 within a limit of 1 : 100,000 as found by us and other experimenters. ^i^ 

 If we slightly increase the heavy water content of the normal water 

 we can assume that, with an accuracy sufficient for our purposes, the 

 heavy water will show the same behaviour as the normal one. As a 

 further argumxcnt in favour of this view, we may quote the results 

 obtained when investigating the behaviour of highly diluted heavy 

 water in the body of fishes. *^2) 



Our first step was to investigate, if water prepared from urine has the 

 same density as the tap water drunk. The result was within 1 : 10^ in 

 the affirmative. The preparation of water from urine was carried out by 

 combined absorption and distillation processes. 55 samples of urine 

 and other excreta were investigated and more than 1000 distillation 



