RETURN FROM PITTSBURG 343 



little stones, assuring me that he had got it himself 

 from the ' mine.' This material contained sundry 

 entire specimens of saltpetre, large as a bean, and 

 showing all the requisite properties. The general 

 opinion being that saltpetre is a salt only to be had 

 artificially, a mine of saltpetre was an important 

 novelty ; and since a few years before an account had 

 been received of such a mine, where from the high 

 price of labor the work could not be carried on, I 

 judged it worth the trouble to bring the matter to the 

 attention of the Government so as to get an investi- 

 gation set on foot. I was commissioned for the 

 purpose, and undertook a journey into the mount- 

 ains, where I first examined the old mine which had 

 been at one time worked. Here the stone got out 

 had been broken up in deep troughs with great 

 pestles, lye-soaked, and the lye boiled, and saltpetre 

 crystallized out, but not sufficiently to bear the costs. 

 This place is on the other side of the southern branch 

 of the Potowmack. I proceeded farther into the 

 mountains ; not far from Patterson's Creek w r as the 

 place whence the nit rum nativuw had been brought 

 me, from a hollow, or cave, in a rock (perhaps 20- 

 30 ft. high) in some places 6, 8-10 ft. deep, and from 

 10 to 15 ft. wide, full of a light earth and many fallen 

 stones ; this hollow was grown over with trees and 

 protected from rain beating in ; inside I found many 

 : small clefts in and between the rocks, large enough 

 ; to hold my hand flat-open, and filled with small, loose 

 ; bits of saltpetre such as had been brought me. Of 

 1 this loose earth I took a bushel, leached it, and boiled 

 ' the lye down to the half which on the following 

 ( morning I found as if a thick brine, to the eye about 



