fluid, the eternity of visible matter winch the vortex theory requires, disappears. Such a visible universe would be as essentially ephemeral as a smoke-ring—so that we may accept it as possible, if not probable, that the visible universe may pass away—that it may bury its dead out of its sight. In its present state we have three forms of development—Chemical, or Stuff-Development, Globe-Development, and Life-Development. It is a question whether the ultimate atoms of chemists are really ultimate; whether some agent, like great heat, for instance, could not split them up into various groups of some primal substance like hydrogen. We see the prospect of a similar simplicity in the development of worlds on the theory of Kant and Laplace, which makes the systems of the universe the result of the gradual condensation of nebulous masses. In the end, all the masses of the universe must fall together—in the beginning there can have been no masses, every thing being nebulous and discrete, even if ordinary matter be indestructible. The last state and the first state of the visible universe are thus separated from each other by a finite duration. A like simplicity may be reached in the development of life. Darwin has made it at least possible that all life may issue from some primordial life-germ. The complete refutation of the doctrine of abiogenesis—the practical proof that life issues only from life—leaves us still bound to account for that germ. There is no doubt that species develop varieties which may ultimately become distinct species, although there is little indication that the varieties of what was once one species are ever separated like species originally different, by a barrier of mutual infertility. A sufficient length of time might enable us to overcome this barrier. In all our developments—the substance-development, the globe-development, the life-development—we are thus brought, in the end, to a something which we are not yet able to comprehend.
"Turning from matter to the phenomena which affect it, we notice one singular set of phenomena in which things insignificant and obscure give rise to great lines of events. A whole mass of water, the temperature of which has been reduced below the freezing-point, suddenly crystallizes on the slightest starting motion; a whole series of tremendous meteorological phenomena, such as hurricanes in the Indian Ocean, happen because certain positions of Mercury and Venus affect the sun's atmosphere, causing spots in his, and the condition of the sun affects the earth. Like the complicated series of effects which follow the pulling of the trigger of a gun, the effects are utterly disproportionate to their causes. Man is a machine of this unstable kind—some trivial change affecting the matter of the brain is all that is needed to set him in motion. May not other beings be capable of touching what we may call the hair-triggers of the universe? Whatever these agencies are, angels or ministering spirits, they certainly do not belong to the present visible universe. The writers examine the sacred records to confirm their speculations."
Proceedings of the American Association for the Advancement of Science. Twenty-third Meeting, held at Hartford, Conn., August, 1874. Salem, 1875.
ThisThis is the annual volume of the American Association, and represents the results of the Hartford meeting in 1874. It opens with the address of the retiring president, Prof. J. Lovering, of Harvard College.
This is concerned with what is called "the great problem of the day," viz., "How to subject all physical phenomena to dynamical laws," and gives an abstract of the various theoretical views on "action at a distance," which, although brilliant, is not fully satisfying.
The practical moral enforced by the address seems to be one designed for American physicists; the moral is that, "unless our physicists are content to lag behind and gather up the crumbs which fall from the rich laboratories and studies of Europe, they must unite to delicate manipulation the power of mathematical analysis."
It is quite true that the mathematics are sadly neglected among us, and of this we have a striking confirmation in this very volume: the only mathematical paper in the whole book is one which demands forty-seven lines for itself, and this is a new demonstration of one of the theorems of Euclid. It is indeed true that our physicists, our scientific men generally, and above all our students, need to recognize, far more than they now do, the value of analysis as a means of research.
We must not forget, however, what in fact is pointed out in this very address, that the basis for mathematical analysis applied to physics must come from labo-
