The Several Forms of Calcium Carbonate. 499 



the factors required for the direct calculation of the solubility- 

 product constant ; whence K A /K B is l - 35. 



In none of the foregoing determinations were all the vari- 

 ables controlled with certainty ; but quite recently Dr. E,. C. 

 Wells — to whom we wish to express our thanks for his kind- 

 ness in enabling us to use his results, part of which are still 

 unpublished* — has determined, in the laboratory of the U. S. 

 Geological Survey, the solubility of both calcite and (artificial) 

 aragonite in water in contact with an atmosphere containing a 

 definite proportion of C0 2 (3*2 parts per 10000) over the tem- 

 perature range 0°-40°. His interpolated results are presented 

 in the subjoined table, along with those of the authors cited 



Table II. 



The ratio of the Solubility-Product Constant of Aragonite (K K ) to that of 

 Calcite (K c ), as derived from various sources. 



Eemarks 



Temp. 



Vk/Vc 



&/ Sc 



Kk/K C 







1-22 



1-8 



18 



1-19 



— 



1-7 



25 



1-19 



— 



1-7 



34 



1-18 



— 



1-6 



8 



1-45 





1-52 



25 



143 



— 



1-44 



41 



142 



— 



1-40 



48 



141 



— 



1-37 



25 







1-35 



49-7 



— 



— 



1-36 



59 



— 



— 



1-24 



18? 



— 



— 



1-35 



25 





1-064 



1-21 



50 



— 



1-075 



1-24 



100 



— 



1-069 



1-22 









1-050 



1-16 



10 



— 



1-053 



147 



20 



— 



1-054 



147 



30 



— 



1-060 



1-19 



40 



— 



1-074 



1-24 



f Kohlrausch (1893); from the 

 J specific conductance (//,) of the 

 ) saturated solution in " pure 



i 



(_ water." 



f Foote (1900); from the specific 

 ! conductance of the saturated 

 \ solution in water saturated with 

 [ CO, at 1 atm. 



Foote (1900) ; from the equi- 

 librium CaC0 3 -f K 2 C O t~» 

 CaC,0 4 + K 2 C0 3 . 



Seyler and Lloyd (1909). 



Kendall (1912). 



Wells (1915); interpolated from 

 his observations. 



The results for calcite are given in J. Wash. Acad., v, 617, 1915. 



