In her new book The Atlantic in World History (Oxford, 2012), Karen Kupperman records an inadvertent and amusing use of a native North American hallucinogen, jimsonweed*, by Virginia troops during Bacon's Rebellion (1676). Gathering the plant for a "boil'd salad," the men
"'turned natural fools upon it for several days: One would blow up a feather in the air, another would dart straws at it with much fury, and another, stark naked was sitting up in a corner, like a monkey, grinning and making mows [moues] at them; a fourth would fondly kiss and paw his companions, and sneer in their faces, with a countenance more antic than any Dutch droll'" (89-90).
It took 11 days for the afflicted men to come to their senses, during which time their companions had to restrain them from "wallow[ing]" in their own filth.
Kupperman also discusses other drugs and stimulants that Europeans discovered in America, including coca, of which one Italian researcher wrote in 1859 "I sneered at all the poor mortals condemned to live in the valley of tears while I, carried on the wings of two leaves of coca, went flying through the space of 77,438 worlds, each more splendid than the one before" (89). I guess he counted all of them.
* Named, apparently, for Jamestown.