DCHP-1 Online
beaver medicine 
"Medicine" is used here in the sense of "magic." See medicine (def. 1). 
the secretion from the scent glands of the beaver used as a lure or as an ingredient in a lure.
See also: beaver castor beaver pride castoreum (def. 1b) medicine (def. 1) (def. 5)
- 1784-1812 (1916) . . . traps for beaver . . . of which the bait is the castorum of the beaver, called the beaver medicine.
- 1907 Beaver medicine and castorum would not allure him [a wily old beaver], and the thought occurred to me to try anise seed oil. . . .
- 1784-1812 (1916) . . . traps for beaver . . . of which the bait is the castorum of the beaver, called the beaver medicine.