ous experience. But after some little time the question was raised whether the effect was not really due to action of heat upon the attenuated vapor of which it was impossible entirely to get rid; and the result of a most careful and elaborate experimental inquiry, in which Nature has been put to the question in every conceivable mode, has been to make it, I believe, almost if not quite certain that the first view was incorrect, and that heat is the real moving power, acting under peculiar conditions, but in no new mode.
No examination of the phenomena of spiritualism can give the least satisfaction to the mind trained in philosophical habits of thought, unless it shall have been, in its way, as searching and complete as this. And when scientific men are invited to dark séances, or admitted only under the condition that they shall merely look on and not inquire too closely, they feel that the matter is one with which they are entirely precluded from dealing. When, again, having seen what appears to them to present the character of a very transparent conjuring trick, they ask for a repetition of it under test-conditions admitted to be fair, their usual experience is that they wait in vain (for hours it may be) for such repetition, and are then told that they have brought an "atmosphere of incredulity" with them, which prevents the manifestation. Now, I by no means affirm that the claims of spiritualism are disproved by these failures; but I do contend that, until the evidence advanced by believers in those claims has stood the test of the same sifting and cross-examination by skeptical experts that would be applied in the case of any other scientific inquiry, it has no claim upon general acceptance; and I shall now proceed to justify that contention by an appeal to the history of previous inquiries of the like kind.
It was about the year 1772 that Mesmer, who had previously published a dissertation "On the Influence of the Planets on the Human Body," announced his discovery of a universal fluid, "the immediate agent of all the phenomena of Nature, in which life originates, and by which it is preserved;" and asserted that he had further discovered the power of regulating the operations of this fluid, to guide its currents in healthy channels, and to obliterate by its means the tracks of disease. This power he in the first instance professed to guide by the use of magnets; but having quarreled with Father Hell, a Professor of Astronomy at Vienna, who had furnished him with the magnets with which he made his experiments, and who then claimed the discovery of their curative agency, Mesmer went on to assert that he could concentrate the power in and liberate it from any substance he pleased, could charge jars with it (as with electricity) and discharge them at his pleasure, and could cure by its means the most intractable diseases. Having created a great sensation in Bavaria and Switzerland by his mysterious manipulations, and by the novel eftects which they often produced, Mesmer returned to Vienna, and undertook to cure