root") obtained from West Africa.If this is ground to a powder and the powder set on fire, it produces a toxic smoke or fume that maddens and kills.
With more bravery than good sense, Holmes tests the substance on himself and on the ever-loyal Watson.Here is how Watson describes the effect:
I had hardly settled in my chair before I was conscious of a thick, musky odour, subtle and nauseous. At the very first whiff of it my brain and my imagination were beyond all control. A thick, black cloud swirled before my eyes, and my mind told me that in this cloud, unseen as yet, but about to spring out upon my appalled senses, lurked all that was vaguely horrible, all that was monstrous and inconceivably wicked in the universe. Vague shapes swirled and swam amid the dark cloud-bank, each a menace and a warning of something coming, the advent of some unspeakable dweller upon the threshold, whose very shadow would blast my soul. A freezing horror took possession of me. I felt that my hair was rising, that my eyes were protruding, that my mouth was opened, and my tongue like leather. The turmoil within my brain was such that something must surely snap. I tried to scream, and was vaguely aware of some hoarse croak which was my own voice, but distant and detached from myself."
A half-century later, the physiological effects of lysergic acid diethylamide (LSD) were discovered—though not in an African root—and the effects were not very different from those Watson described.It seems that Holmes and Watson had the equivalent of a "bad trip" decades before its time.
This is a remarkable bit of chemical science-fiction that came true, and it makes up to me for all the bits of poor chemistry Conan Doyle inserted into his stories.