[When my father was at the Water-cure Establishment at Malvern he was brought into contact with clairvoyance, of which he writes in the following extract from a letter to Fox, September, 1850. "You speak about Homoeopathy, which is a subject which makes me more wrath, even than does Clairvoyance. Clairvoyance so transcends belief, that one's ordinary faculties are put out of the question, but in homoeopathy common sense and common observation come into play, and both these must go to the dogs, if the infinitesimal doses have any effect whatever. How true is a remark I saw the other day by Quetelet, in respect to evidence of curative processes, viz., that no one knows in disease what is the simple result of nothing being done, as a standard with which to compare homoeopathy, and all other such things. It is a sad flaw, I cannot but think, in my beloved Dr. Gully, that he believes in everything. When Miss -- was very ill, he had a clairvoyant girl to report on internal changes, a mesmerist to put her to sleep--an homoeopathist, viz. Dr. --, and himself as hydropathist! and the girl recovered." A passage out of an earlier letter to Fox (December, 1884) shows that he was equally sceptical on the subject of mesmerism: "With respect to mesmerism, the whole country resounds with wonderful facts or tales..I have just heard of a child, three or four years old (whose parents and self I well knew) mesmerised by his father, which is the first fact which has staggered me. I shall not believe fully till I see or hear from good evidence of animals (as has been stated is possible) not drugged, being put to stupor; of course the impossibility would not prove mesmerism false; but it is the only clear experimentum crucis, and I am astonished it has not been systematically tried. If mesmerism was investigated, like a science, this could not have been left till the present day to be DONE SATISFACTORILY, as it has been I believe left. Keep some cats yourself, and do get some mesmeriser to attempt it. One man told me he had succeeded, but his experiments were most vague, and as was likely from a man who said cats were more easily done than other animals, because they were so electrical!"] CHARLES DARWIN TO C. LYELL. Down, December 4th [1849]. My dear Lyell,