This is right up my alley, but sadly I never ran across any
references to Twain and galvanic experiments on corpses.

On Twain and electricity and death, I can refer you (if you'll
forgive a shameless plug) to the discussion at the very end of my
_Edison & the Electric Chair_ (Walker, 2003), which links the mass
electrocution episode in _Yankee_ with the 'battle of the currents'
between Thos. Edison and George Westinghouse for supremacy in the
electrical industry. That episode in _Yankee_ was, I believe,
inspired by a rash of accidental deaths in Manhattan in 1888 and 1889
caused by poorly installed electrical wires.  It also may have been
Twain's veiled commentary on the electric chair, the most notorious
product of the battle of the currents. W.D. Howells, incidentally,
wrote a cutting early critique of the electric chair.

On Twain and the electric chair, also see H. Bruce Franklin's _War
Stars_ and his article on _Billy Budd_ in _American Literature_ 69
(1997):337.

On galvanic corpse experiments having nothing whatsoever to do with
Twain (although one of them took place in Missouri in 1870), see pp.
42-3 of _Edison & the Electric Chair_.

Mark Essig
Los Angeles, CA