308 Headden — Group of Radium-hearing Springs. 



Per cent. 



Organic matter, etc.. 7-82 



CaC0 3 _ 43-39 



BaS0 4 _ _ 48-79 



Sr, K, Na and Li _ _ _ Traces 



100-00 



_ The Bath Tub furnishes the finest samples of this baritic 

 sinter. The spring is lined with a pure cellular barite. The 

 sample which I used as a source of this barite for analysis was 

 from the Bath Tub, but was chosen to represent an average 

 sample of this sinter as it occurs near the springs. 



Analyses of Sinter prom the Bath Tub. 



Per cent. 



Soluble in acetic acid 15-46 



Soluble in HC1 cone, not soluble in acetic 1-33 



Insoluble, BaS0 4 _ 83*21 



100-00 

 Analysis of the insoluble portion. 



SiO a . . _ 3-25 



SO s _ 32-25 



A1 '° 3 I 0-80 



BaO _ 63-00 



CaO _ 0-30 



SrO _._... 0-45 



MgO _ Trace 



K 2 0-17 



Na 2 with heavy trace of lithia 0*29 



100-51 



The barium determination is too high ; the chromate should 

 have been reprecipitated a second time. 



The examination of these samples of sinter show that the 

 bed passes from a calcareous sinter carrying a few per cent of 

 baric sulphate to a pure barite sinter at some of the springs. 

 This I believe to be a unique fact. Frequent mention is made 

 of the occurrence of barium in mineral springs, mostly in 

 traces, but I have found mention of only one water which 

 deposited baric sulphate, a mine water in England. 



I have stated that I regret not having yet examined the 

 gases given off by these springs. I am fully convinced that 

 they contain helium, for these waters contain, as I shall now 

 show, comparatively abundant quantities of radium. 



