In the first section of this book, an attempt has been made to give some idea of the present state of molecular science—far short, indeed, of so extensive a subject; yet it may be sufficient, perhaps, to show the views now entertained with regard to the powers of nature, the atoms of matter, and the general laws resulting from the phenomena of their reciprocal action. By spectrum analysis it has been shown that not only many terrestrial substances, in a highly attenuated state, are constituents of the luminous atmospheres of the sun and stars, but that the nebulæ in the more distant regions of space contain some of the elementary gases of the air we breathe.
In the succeeding sections it has been proved that the atmosphere teems with the microscopic germs of animal and vegetable beings, waiting till suitable conditions enable them to spring into life, and perform their part in the economy of the world. The life history of the lower classes of both kingdoms has been a triumph of microscopic science.
The molecular structure of vegetables and animals has been investigated by men of science in their minutest details; the fragment of a tooth, bone, or shell, recent or fossil, is sufficient to determine the nature of the animal to which it belonged; and, if fossil, to assign the geological period at which it had lived, whether on the earth, in the waters, or the air. By the microscopic examination of a minute Foraminifer or shell-like organism, it has been proved beyond a doubt that the Eozoön, an animal which existed at a geological period whose remoteness in time carries us far beyond the reach of imagination, only differs in size from a kind living in the present seas. Simplicity of structure has preserved the race through all the geological changes which, during millions of centuries, have swept from existence myriads of more highly organized beings. The Eozoön is the most ancient form of life known, and was probably an inhabitant of the primeval ocean. Patches of carbonaceous matter imbedded in the same strata show that vegetation had already begun; so at that most remote period of the earth’s existence, the vivifying influence of the sun, the constitution and motions of the atmosphere and ocean, and the vicissitudes of day and night, of life and death, were the same as at the present time.
Footnotes
[1]. The nervous system is ably explained in Dr. Carpenter’s ‘Manual of Physiology.’
[2]. A pointer and greyhound, belonging to a friend of the author’s, repeatedly brought home hares. Upon watching the dogs, the pointer was seen to find the hare, which was coursed and killed by the greyhound. Singular as this may seem, it is by no means unprecedented.
[3]. From rhizon, a root, and pous, podos, a foot.
[4]. ‘On the Amœba princeps and its reproductive cells,’ by Mr J. H. Carter: Annals of Natural History, July 1863.
[5]. ‘On Difflugian Rhizopods,’ by G. C. Wallich M.D. Annals of Natural History, March, 1864.
[6]. Dr. Wallich.