then thrown into it, nothing separates but ice, which comes to the surface. If we throw in a little anhydrous salt, nothing but the anhydrous salt separates out, and that sinks to the bottom. But if we throw into it a crystal of a previous crop of cryohydrate, then nothing but the cryohydrate separates. In this case also, like evidently excites like only, in obedience to physical laws. (Addresses, Science Conferences; South Kensington Museum, 1876; Vol. 2, p. 108). Even two clocks, when hung near each other, against a board or surface which readily transmits vibrations, have been known to exhibit, by synchronous action, an apparent sympathy, which changed their rate of going. Periodical phenomena, also, brought about by definite causes, occur in mental, as well as in physical phenomena. In the former we have the phenomena of sleep, and in the latter, definite causes produce summer and winter, day and night, the tides, cycles of solar spots, maxima and minima of magnetic intensity, etc., etc. Conversely to the manifestation of the principles of {118} inanimate matter by living bodies and in mental action, so have modern inventions demonstrated the possibility of the performance by inanimate substances and apparatuses, of the functions, not only of our bodily organs, (as of locomotion by the steam engine,) but also of our senses and intellect, and in some cases, to a degree far surpassing unaided human power. Apparatus, sensitive to sound, have been constructed, as in the microphone and singing-flames; others capable of reproducing articulate speech, as in the phonograph, telephone, etc.; others again sensitive to light, as in the production of visible images by photography, and reproducing them at a distance through wires by means of the photophone; the power of indicating or foretelling future events has also been embodied in instruments called "tide predictors," and that of evolving inferences has been shewn in Jevon's "Logical machine." The various facts mentioned in this chapter prove that mind agrees with the various forms of physical energy in many essential points, and obeys many of the same laws or principles. Examine whatever general phenomena of the mind we may, we can always detect some apparent or real connection of them with the great principles of inorganic nature; and in order to prove the dependence of them upon the great principles of science it is not necessary to show that all such actions are subject to those principles. Until the whole is explained however, there will always remain mysterious phenomena to cavil about. {119} MORAL PROGRESS. At the present time few competent persons have largely investigated the fundamental relations of morality to Physical Science, consequently moral actions are usually considered not to have a scientific basis, and the doctrine is still extensively taught that some moral phenomena are essentially supernatural.