1To Thomas Jefferson from Samuel Brown, 17 March 1797 (Jefferson Papers)
...the society papers and specimens, including saltpetre rock and mammoth bones from a...
2To Thomas Jefferson from Palisot de Beauvois, 25 April 1798 (Jefferson Papers)
...printed. One of the workers in the saltpeter which is abundantly mined in that underworld...
3To Thomas Jefferson from Bishop James Madison, 17 January 1800 (Jefferson Papers)
. Is it not probable, that the Saltpeter which abounds in the Part of the Country where thes...