THE CHEMICAL EVOLUTION OF THE OCEAN 



225 



A diagram was also shown in which, alongside Dana's geo- 

 logical column (which is proportioned according to his estimates 

 of the lengths of the geological periods), the sodium: chlorine ratio, 

 and computed ages of various brines, were laid off horizontally, 

 which diagram was constructed from Table I. 



TABLE IV 



(keweenawan water analyses (grams per kilo) 



1. Is the water from the boiler of the vertical shaft of the Calumet and Hecla 

 Mine, about 5,000 feet deep, but containing more or less surface water, by Heath. 

 See Annual Report, 1903, p. 166. 



2. Tamarack cross-cut, 4,300 feet deep-^A. C. Lane, sampler; F. B. Wilson, 

 analyst. 



3. Freda Well, Annual Report, 1903, p. 166. 



4. Wolverine Mine — seventeenth level — A. C. Lane, sampler; F. B. Wilson, 

 analyst. 



