238 



HENRY IV. NICHOLS 



to indicate the percentage composition of the soluble portion 

 (on the assumption that the analyses are complete) they com- 

 pare as follows : 



SALTS LEACHED FROM SUBSOIL AND FROM CAVE EARTH, MAM- 

 MOTH CAVE 



1. Subsoil. . . . 



2. Cave earth. 



Na„0+K 2 



15-32 

 28.94 



CaO 



9.58 

 20.54 



so, 



28.72 



42. 10 



PoO E 



tr. 

 0.00^ 



N„0 = 



36.17 

 8.30 



NH 4 



10.21 

 00.001 



The resemblance is purely qualitative, and it is very evident 

 that the second substance could not be formed by the evapora- 

 tion of a solution of the first as the theory requires. The water 

 which enters the cave forms stalactites and stalagmites and, 

 therefore, must carry carbonate of lime. In the aqueous extract 

 from the subsoil, considered below, the bases are saturated with 

 nitric and sulphuric acid and hence it contains no carbonates. 

 This analysis therefore does not represent the waters which enter 

 the cave. It is most probable that these waters after leaving 

 the subsoil take up carbonate of lime and other material while 

 passing through the rock roof and enter the cave with the com- 

 position of the drip water whose analysis is given by Mr. Hess 

 {loc. cit., p. 132). 



From the analysis of waters dripping into Mammoth Cave 

 made by Mr. Hess, the figures below have been derived calculat- 

 ing the ratio of certain salts for comparison with the soluble 

 salts from the cave earths of Mammoth and Saltpeter Caves, 

 also recalculated from Mr. Hess' analyses. 



SALTS LEACHED FROM CAVE EARTH COMPARED WITH CORRE- 

 SPONDING SALTS FROM DRIP WATER 



