plicated in the universal transformations of matter. It turned out that hydrogen not oxygen is the great acidifying principle, and not only so, but it is the base-producing principle, while the old and antagonizing classes of acids and bases disappeared as separate groups and were merged in one great division of hydrates. Hydrogen, moreover, by its remarkable properties and position has become the unit and standard of the modern chemical system, and, though less abundant upon earth than oxygen, it is the grand element of the sun, has been detected in the remotest stellar luminaries, in the mysterious nebulae, and blazed out in a mighty conflagration of one of the most distant stars. Such is the part played by that form of matter which is the most attenuated, ethereal, and "nearest to nothing," of any we know.
It is an essential part of Mr. Spencer's method of treating sociological science to trace the genesis of the fundamental ideas which have become embodied in social institutions. The installment of his work now before us is devoted to the origin and development of religious ideas. These have been powerful in all ages, in all places, and in all grades of society, in influencing human conduct, and in determining the constitution of the social state. In this country religion is largely differentiated from government; but it remains at the basis of extensive and important institutions. In European nations, and in most countries in fact all over the world, religious establishments are still part of the state organization and potent factors in determining the structure of society. An element of the social state, so universal and pertaining to humanity itself, is certainly a fit subject for scientific elucidation. For, although it is claimed in special cases that religious ideas are not of natural but of supernatural origin, and therefore not amenable to the scientific method of investigation, yet those who entertain this view always limit it to a particular case. The believers in the supernatural origin of religious conceptions generally restrict their view to the one religion which they hold to be true. But, although the implication is that all other religions are false, they still remain to be accounted for, so that, admitting the super-natural character and origin of a single system of faith, there yet remain hundreds of other systems of all complexions and gradations which are the legitimate subjects of study from the scientific point of view. A Christian may hold his system to be preternaturally given, and its origin to be not open to scientific scrutiny or criticism; but he cannot object to the employment of science in tracing out the development of religious notions among heathen and savages. There is, therefore, plenty of legitimate room to carry on the inquiry.
In this number of his work Mr. Spencer devotes himself to tracing the origin and growth of religious ideas, that in their various forms may be regarded as universal. His aim is to show that they are natural and necessary outgrowths of the intercourse with Nature of the human mind before it has learned any thing of the true order of Nature. In his successive chapters he treats of "The Ideas of Death and Resurrection," "The Ideas of Souls, Ghosts, Spirits, Demons, etc.," "The Ideas of another Life," "The Ideas of another World," "The Ideas of Supernatural Agents." The argument, as is usual with Mr. Spencer, is able, the analysis clear, and the presentation forcible. The work is full of fresh and interesting information regarding the mental states and habits of the lower races of mankind, and the accompanying psychological discussion gives an impressive interest to the facts.