I remember, upon the occasion of my inhaling the nitrous oxide at the Royal Institution, about five minutes afterwards, a gentleman came from the other side of the theatre and said to me, "Was it not ravishingly delightful, Sir?" "It was highly pleasurable, no doubt." "Was it not very like sweet music?" "I cannot say I perceived any analogy to it." "Did you not say it was very like Mrs. Billington singing by your ear?" "No, Sir, I said that while I was breathing the gas, there was a singing in my ears."
To return, however, to dreams, I not only believe, for the reasons given, but have more than once actually experienced that the most fearful forms, when produced simply by association, instead of causing fear, operate no other effect than the same would do if they had passed through my mind as thoughts, while I was composing a faery tale; the whole depending on the wise and gracious law in our nature, that the actual bodily sensations, called forth according to the law of association by thoughts and images of the mind, never greatly transcend the limits of pleasurable feeling in a tolerably healthy frame, unless where an act of the judgment supervenes and interprets them as purporting instant danger to ourselves.
There
have been very strange and incredible stories told of and by the alchemists. Perhaps in some of them there may have been a specific form of mania, originating in the constant intension of the mind on an imaginary end, associated with an immense variety of means, all of them substances not familiar to men in general, and in forms strange and unlike to those of ordinary nature. Sometimes, it seems as if the alchemists wrote like the Pythagoreans on music, imagining a metaphysical and inaudible music as the basis of the audible. It is clear that by sulphur they meant the solar rays or light, and by mercury the principle of ponderability, so that their theory was the same with that of the Heraclitic physics, or the modern German
Naturphilosophie,
which deduces all things from light and gravitation, each being bipolar; gravitation=north and south, or attraction and repulsion; light=east and west, or contraction and dilation; and gold being the tetrad, or interpenetration of both, as water was the dyad of light, and iron the dyad of gravitation.
It is, probably, unjust to accuse the alchemists generally of dabbling with attempts at magic in the common sense of the term. The supposed exercise of magical power always involved some moral guilt, directly or indirectly, as in stealing a piece of meat to lay on warts, touching humours with the hand of an executed person, &c. Rites of this sort and other practices of sorcery have always been regarded with trembling abhorrence by all nations, even the most ignorant, as by the Africans, the Hudson's Bay people and others. The alchemists were, no doubt, often considered as dealers in art magic, and many of them were not unwilling that such a belief should be prevalent; and the more earnest among them evidently looked at their association of substances, fumigations, and other chemical operations as merely ceremonial, and seem, therefore, to have had a deeper meaning, that of evoking a latent power. It would be profitable to make a collection of all the cases of cures by magical charms and incantations; much useful information might, probably, be derived from it; for it is to be observed that such rites are the form in which medical knowledge would be preserved amongst a barbarous and ignorant people.