242 



HENRY W. NICHOLS 



Mammoth and the other caves considered, yet the above con- 

 clusion may be confirmed for the State of Kentucky by the 

 following figures from the analyses of rock and soil made for 

 the Kentucky Geological Survey. 1 



Substance. P 2 5 , per cent. 



Subsoil -------- 0.440 



Red underclay ------ 0.425 



Limestone ------- 0.221 



Limestone ------- 0.196 



Subsoil, Bourbon county - - 



Underclay - - 



Limestone ------ 



Limestone ------- 



No. 



570 



571 

 572 



573 

 576 

 577 

 578 

 579 

 614 

 615 



663 



664 

 666 



683 

 684 

 685 



Subsoil 

 Limestone 



Virgin soil, Jessamine county 

 Virgin soil, Jessamine county 

 Limestone - 



Subsoil - 



Underclay 



Limestone 



0.243 

 0.221 

 0.093 

 0.183 



0.316 

 0.311 



0.239 

 0.666 

 0.567 



o.459 

 0.456 

 0.631 



In preparing the above table all cultivated soils have been 

 excluded, and it is believed that only examples of virgin soils, 

 subsoils and underlying limestones that are properly comparable 

 have been included. The average of these figures is 0.315 per 

 cent. P 3 O g for the limestones and 0.365 per cent. P 3 O s for the 

 soils. The average of twenty-five analyses of subsoils overlying 

 limestone in Kentucky is 0.264 per cent. P 3 5 . Mr. Hess finds 

 2.62 per cent. P 3 O g in bat guano and 2.10 per cent. P 3 5 in cave 

 earth. This is obviously a far greater proportion of phosphate 

 than is found in other residual clays, and as in the drip water 

 he finds only a trace of phosphate with 53.61 milligrams car- 

 bonate of lime, the difference can hardly be made up from that 

 source. On the other hand, the bat guano provides an abundant 

 supply, as all the phosphorus used in the metabolic processes of 

 bat life must eventually find its way to the guano. Finally, it 



1 Third Report Geol. Surv. Kentucky. 



