" ... 'tis called by the Moors, Gange, by the Chingalese, Comsa, and by the Portugals, Bangue ... (it) doth in a short Time, quite take away the Memory and Understanding, so that the patient understands not, nor remembereth any thing that he seeth, heareth, or doth, in that Exstasie, but becomes, as it were, a mere Natural, being unable to speak a Word of Sense; yet he is very merry, and laughs, and sings, and speaks Words without any Coherence, nor knowing what he saith or doth; yet he is not giddy, or drunk, but walks and dances, and sheweth many odd Tricks; after a little time he falls asleep, and sleepeth very soundly and quietly; and when he wakes, he finds himself mightily refresh'd, and exceeding hungry ...
'tis commonly made Use of, by the Heathen Priests, or rambling Mendicant Heathen Friars, who will many of them meet together, and every of them dose themselves with this Medicine, and then ramble several Ways, talking they know not what, pretending after that, they were inspired."
Robert Hooke, describing the effects of cannabis to a meeting of the Royal Society in London, 18th December 1689. (from Stephen Inwood's Hooke biography The Man Who Knew Too Much).
(The Chingalese are the Ceylonese, and the charming and sympathetic expression 'a natural' was used until the early twentieth century to describe a simpleton or mentally backward person. There's an echo there of the concept that the afflicted one was in some way sacred or touched by God. Today a natural would be described as having severe learning difficulties.)