6 RECONNOISSANCE OF THE LYON NITRATE PROSPECT. 



hypothesis is negatived by the nature of the rock in which the mate- 

 rial is found. This rock is almost certainly of marine origin, and 

 largely the result of chemical precipitation under water. It is nearly 

 inconceivable that primary nitrate would be associated with it, and 

 there is no known reaction or process by which nitrate could have 

 been formed secondarily within its mass. 



But whatever may be the source of the nitrate, it is obvious that 

 there is not enough of it to have any important commercial value. 

 The surface rocks as sampled contain too little material to be profit- 

 ably worked by any known method or any method likely to be dis- 

 covered, and there is no reason to believe that the rock would increase 

 in grade as one penetrated within it. Indeed I am of the opinion 

 that the reverse would be the case, and that the portions at and 

 near the surface contain more nitrate than the rock within. This fol- 

 lows from the tendency of percolating waters to concentrate all sol- 

 uble materials, including nitrates, at a surface where they undergo 

 evaporation. 



Approved. 



JAMES WILSON, 



Secretary of Agriculture . 



i 

 WASHINGTON, D. C., January 29, 1912. 



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