Donovan's Brain by Curt Siodmak

The SF classic novel of the terror that lurked in DONOVAN'S BRAIN.
DEAD...Doomed by disease, then mangled in a plane crash, there was no doubt that Donovan was dead.
YET...floating in a tank of nutrient, linked to complex apparatus, Donovan's brain still lived...
ALIVE...someone walked with Donovan's gait, wrote his signature, knew his foulest secrets-and carried out his last, weirdest plan!
"Donovan's Brain is terrific!"-THE NEW YORK TIMES