EFFECTS OF GASES ON TROUT. 



355 



An examination of this water by Mr. Florance and the author 

 showed it to be fairly rich in radium emanation, a result not 

 at all surprising when one bears in mind that radium appears to 

 be widespread in small quantities throughout the crust of the 

 earth. 



To show the contents of the radio-activity the following 

 figures taken as example from a paper by Farr and Blorance^ 

 may be quoted : — 



Many others of the Christchurch wells were examined and all found 

 raidio-active ; but as those above comprise all that will subse- 

 quently be referred to, these are all that need now be given. The 

 mode employed to indicate the radio-activity is quite arbitrary, 

 being the rate in scale divisions per minute of the motion of the 

 leaf of an electroscope across the field. 



For the purpose of subsequent comparison with other water 

 it will be well to state that the maximum radium emanation content 

 of a standard solution of radium received from Professor Rutherford, 

 and containing 3-925 x 10"^^ gramme of radium, gave a leak of 64 

 scale divisions per minute. 



It may also be of interest to give at the same time the radium 

 emanation content of some of the famous Continental springs. 

 Thus : — ■ 



Plonbices, source Vauquelin . . . , . . . . 376 



,, iron des Capucin . . . . . . . . 787 



Aix les Bains, No. 1 . . . . • . . . . . . 461 



„ No. 2 257 



Born des Saviej , source Le Lynne .. .. .. 169 



In the case of the Christchurch water the effect is due to 

 radium emanation, and no dissolved radium was discovered in the 

 water, and in every case a litre of water was used. 



As, therefore, the Christchurch water is radio-active to a 

 degree comparable with that of other subterranean sources of 

 supply, a search was made for any effects which might possibly be 

 due to radium emanation, etc. Naturally, the trout inhabiting 

 the streams fed by these wells were examined as being likely to 

 show any effects which were to be found. Several very remarkable 

 results, were discovered, which, whether they be ascribable to 



1 Trans. N.Z. Inst., Vol. XLU., page 186. 



