Wellcome Library page
(there's a download link to the left)
Though I've poked around the Wellcome Library's remarkable digital archive I missed this, learning about it from the Paris Review of all places. There's practically no information about the book - the Wellcome dates it possibly to 1775 and that's about it. All the other references I find are to this copy and give no background.
In any case it's the jaw-dropping illustrations that draw attention (some possibly NSFW if that matters). Several are familiar magickal designs but others are practically outsider or surrealist, almost begging for psychoanalytic attention. Or maybe the cover of a metal album - you never know.
