*

It appears highly probable from recent discoveries, that light is not a material substance, but only an effect of undulations of ether; that this infinitely subtle and elastic ether pervades all space, and even the interior of all bodies; so long as it remains at rest, there is total darkness; when it is put into a peculiar state of vibration, the sensation of light is produced: this vibration may be excited by various causes ; e. g. by the sun, by the stars, by electricity, combustion, &c. If then light be not a substance, but only a series of vibrations of ether, i. e. an effect produced on a subtile fluid, by the excitement of one or many extraneous causes, it can hardly be said, nor is it said, in Gen. i. 3, to have been created, though it may be literally said to be called into action.

Lastly, in the reference made in the Fourth Commandment, Exod. xx. 11, to the six days of the Mosaic creation, the word asah, "made," is the same which is used in Gen. i. 7, and Gen. i. 16, and which has been shown to be less strong and less comprehensive than bara, "created;" and as it by no means necessarily implies creation out of nothing, it may be here employed

For a general statement of the undulatory theory of light, see Sir John Herschell, art. Light, part iii. sec. 2. Encyc. Metropol. See also Professor Airy's Mathematical Tracts, 2nd edit. 1831, p. 249; and Mrs. Somerville's Connexion of the Physical Sciences, 1834, p. 185.

See Note, p. 26.

to express a new arrangement of materials that existed before.*

After all, it should be recollected that the question is not respecting the correctness of the Mosaic narrative, but of our interpretation of it; and still further, it should be borne in mind that the object of this account was, not to state in what manner, but by whom, the world was made. As the prevailing tendency of men in those early days was to worship the most glorious objects of nature, namely, the sun and moon and stars; it should seem to have been one important point in the Mosaic account of creation, to guard the Israelites against the Polytheism and idolatry of the nations around them; by announcing that all these magnificent celestial bodies were no Gods, but the works of One Almighty Creator, to whom alone the worship of mankind is due.†

*See Note, p. 22.

+ Having thus far ventured to enter into a series of explanations, which I think will reconcile even the letter of the text of Genesis with the phenomena of Geology, I forbear to say more on this important subject, and have much satisfaction in being able to refer my readers to some admirable articles in the Christian Observer (May, June, July, August, 1834) for a very able and comprehensive summary of the present state of this question; explaining the difficulties with which it is surrounded, and offering many temperate and judicious suggestions, as to the spirit in which investigations of this kind ought to be conducted. I would also refer to Bishop Horsley's Sermons, 8vo. 1816, vol. iii. ser. 39; to Bishop Bird Sumner's Records of Creation, vol. ii. p. 356; Douglas's Errors regarding Religion, 1830, p. 261-264,

CHAPTER III.

Proper Subjects of Geological Enquiry.

THE history of the earth forms a large and complex subject of enquiry, divisible at its outset, into two distinct branches; the first, comprehending the history of unorganized mineral

Higgins on the Mosaical and Mineral Geologies, 1832; and more especially to Professor Sedgwick's eloquent and admirable discourse on the Studies of the University of Cambridge, 1833, in which he has most ably pointed out the relations which Geology bears to natural religion, and thus sums up his valuable opinion as to the kind of information we ought to look for in the Bible: "The Bible instructs us that man, and other living things, have been placed but a few years upon the earth; and the physical monuments of the world bear witness to the same truth: if the astronomer tells us of myriads of worlds not spoken of in the sacred records; the geologist, in like manner, proves (not by arguments from analogy, but by the incontrovertible evidence of physical phenomena) that there were former conditions of our planet, separated from each other by vast intervals of time, during which man, and the other creatures of his own date, had not been called into being. Periods such as these belong not, therefore, to the moral history of our race, and come neither within the letter nor the spirit of revelation. Between the first creation of the earth and that day in which it pleased God to place man upon it, who shall dare to define the interval? On this question scripture is silent, but that silence destroys not the meaning of those physical monuments of his power that God has put before our eyes, giving us at the same time faculties whereby we may interpret them and comprehend their meaning."

matter, and of the various changes through which it has advanced, from the creation of its component elements to its actual condition; the second, embracing the past history of the animal and vegetable kingdoms, and the successive modifications which these two great departments of nature have undergone, during the chemical and mechanical operations that have affected the surface of our planet. As the study of both these branches forms the subject of the science of Geology, it is no less important to examine the nature and action of the physical forces, that have affected unorganized mineral bodies, than to investigate the laws of life, and varied conditions of organization, that prevailed while the crust of our globe was in process of formation.

Before we enter on the history of fossil animals and vegetables, we must therefore first briefly review the progressive stages of mineral formations; and see how far we can discover in the chemical constitution, and mechanical arrangement of the materials of the earth, proofs of general prospective adaptation to the economy of animal and vegetable life.

As far as our planet is concerned, the first act of creation seems to have consisted in giving origin to the elements of the material world, These inorganic elements appear to have received no subsequent addition to their number,

and to have undergone no alteration in their nature and qualities; but to have been submitted at their creation to the self same laws that regulate their actual condition, and to have continued subject to these laws during every succeeding period of geological change. The same elements also which enter the composition of existing animals and plants, appear to have performed similar functions in the economy of many successive animal and vegetable creations.

In tracing the history of these natural phenomena we enter at once into the consideration of Geological Dynamics, including the nature and mode of operation of all kinds of physical agents, that have at any time, and in any manner, affected the surface and interior of the earth. In the foremost rank of these agents, we find Fire and Water,-those two universal and mighty antagonizing forces, which have most materially influenced the condition of the globe; and which man also has converted into the most efficient instruments of his power, and obedient auxiliaries of his mechanical and chemical and culinary operations.

The state of the ingredients of crystalline rocks has, in a great degree, been influenced by chemical and electro-magnetic forces; whilst that of stratified sedimentary deposits has resulted chiefly from the mechanical action of moving water, and has occasionally been modi