1George F. Hopkins to Thomas Jefferson, [received 29] August 1822 (Jefferson Papers)
Observations on Electricity, Looming, and Sounds (“Hortensius” [G. F. Hopkins]) [index entry]
2Thomas Jefferson to George F. Hopkins, 5 September 1822 (Jefferson Papers)
Observations on Electricity, Looming, and Sounds (“Hortensius” [G. F. Hopkins]) [index entry]