By the experiments here referred to by this author, he had endeavored to show, that even the light of the stars exerted an odylic influence upon the human system; that is, certain effects independent altogether of their light; and if there be no mistake in the experiments, they certainly do show this. Such a fact almost realizes the suggestions already made, that beings in other spheres may possess such an exaltation of sensibilities as to be able to learn what is going on in this world, and that it is easy to conceive how our sensorium may be raised to the same exalted pitch.
My fifth argument, illustrative of the general principle, is based upon chemical reaction.
Mechanical reaction changes the form and position of bodies; chemical reaction alters their constitution. By the decomposition of some compounds, the elements are obtained for forming others; and such changes are going on around us and within us in great numbers unperceived. In the worlds above us, and in the earth beneath us, from its circumference to its centre, the transmutations of chemistry are in progress, and many of them are modified by the agency of man; so that here is another channel through which human actions exert an influence upon the material universe, and to an extent which we cannot measure. Let us look at some of the modes in which this is done.
Take, in the first place, the facts respecting photography, or the art of obtaining sketches of objects by means of the action of light. This is strictly a chemical process. In a beam of light, that comes to us from the sun, we find not only rays of light and heat, but chemical rays, which act upon some bodies to change their constitution. When these rays are reflected from a human countenance, and fall upon a silvered plate, that has been coated with iodine and bromine, they leave an impression, which is fixed and brought out as a portrait by the vapor of mercury and some other agents. Here the chemical changes produced by these rays are exceedingly perfect; but they produce effects upon many other substances, artificially or naturally prepared; such as paper, for instance, immersed in a solution of bichromate of potash, or upon vegetation, whose green color is probably the result of this action, (as is obvious from the fact that plants growing in the dark are destitute of color.) Indeed, a large part of the changes of color in nature depend upon these invisible rays.
It seems, then, that this photographic influence pervades all nature; nor can we say where it stops. We do not know but it may imprint upon the world around us our features, as they are modified by various passions, and thus fill nature with daguerreotype impressions of all our actions that are performed in daylight. It may be, too, that there are tests by which nature, more skilfully than any human photographist, can bring out and fix those portraits, so that acuter senses than ours shall see them, as on a great canvas, spread over the material universe. Perhaps, too, they may never fade from that canvas, but become specimens in the great picture gallery of eternity.
The thought may perhaps cross some mind, that, though those human actions which are performed in sunlight may be imprinted upon the universe, yet no deed of darkness can thus reveal its author, and remain an eternal stigma upon his name. But there is another phase to this subject. What is the evidence that the chemical rays of a sunbeam are rays of light? We know that they are unequally diffused through the spectrum, being most energetic at its violet extremity; but there is no proof that they are visible. They may, like heat, exert their appropriate influence, which seems to be mainly that of deoxidation, and yet not be colorific. If so, we might expect them to operate in the dark; and experiment proves that they do. An engraving on paper, placed between an iodized silver plate and an amalgamated copper plate, was left in the dark for fifteen hours. On exposing the amalgamated plate to the vapor of mercury, “a very nice impression of the engraving was brought out—it having been effected through the thickness of the paper.”—Mr. Hunt, “On the Changes which Bodies are capable of undergoing in Darkness,” Phil. Mag. vol. xxii. p. 277.—Many like experiments prove the existence; among bodies, of a power analogous to, if not identical with, that which accompanies light, and is the basis of the photographic process. Some philosophers do not regard them as identical. But this is of little consequence in my present argument. For all agree that there is a power in nature capable of impressing the outlines of some objects upon others in total darkness.
In respect to such cases, there are one or two facts deserving of special notice. And, first. We must not infer, because man has yet been able to bring out to human view but a few examples of this sort, that they are, therefore, few in nature. Rather should the discovery of a few lead to the conclusion that nature may be full of them, and that a more delicate and refined chemistry may yet disclose them. For the few known cases give us a glimpse of a recondite law of nature, which most likely pervades creation. Some regard these dark rays as neither light, nor heat, nor chemical rays, but a new element; but, whatever its nature, no reason can be given why it should operate only in a few cases, and those of artificial preparation. More probably, through this influence, all bodies brought into contact, or proximity, impress their images upon one another; and the time may come, when, touched by a more subtile chemistry than man now wields, these images shall take a place among obvious and permanent things in the universe, to the honor and glory of some, but to the amazement and everlasting contempt of more.
Of more, I say; for wickedness has oftener sought the concealment of darkness than modest virtue. The foulest enormities of human conduct have always striven to cover themselves with the shroud of night. The thief, the counterfeiter, the assassin, the robber, the murderer, and the seducer, feel comparatively safe in the midnight darkness, because no human eye can scrutinize their actions. But what if it should turn out that sable night, to speak paradoxically, is an unerring photographist! What if wicked men, as they open their eyes from the sleep of death, in another world, should find the universe hung round with faithful pictures of their earthly enormities, which they had supposed forever lost in the oblivion of night! What scenes for them to gaze at forever! They may now, indeed, smile incredulously at such a suggestion; but the disclosures of chemistry may well make them tremble. Analogy does make it a scientific probability that every action of man, however deep the darkness in which it was performed, has imprinted its image upon nature, and that there may be tests which shall draw it into daylight, and make it permanent so long as materialism endures.
There is another chemical principle, called catalysis, through which human actions may make powerful and permanent impressions on the universe, and that, too, unperceived by man. In some cases, the mere presence of a certain agent, in a small quantity, will produce extensive changes of constitution in other bodies, while the agent itself remains unaltered. Thus a strip of platinum will determine the union of oxygen and hydrogen in the platinum lamp; and sulphuric acid, in a solution of starch, will change it first into gum, and then into sugar; while neither the platinum nor the acid experiences any change. These are called catalytic changes. More often, however, the catalytic agent is itself in the process of change, and it produces an analogous change in other bodies. A familiar example is yeast, or ferment. This substance contains a principle called diastase, one part of which is capable of converting two thousand parts of starch into sugar; and this is what is done in the familiar process of fermentation, when we always see verified the scriptural declaration, A little leaven leaveneth the whole lump.
The precise manner in which the diastase operates in these cases we may not be able to explain. The particles of the diastase, being themselves in motion, possess the power of putting in motion the particles of other bodies; and these, again, operate upon others, and so on, often to an astonishing extent. In the case of the platinum and the acid, however, no change takes place in their molecules, and we can only state it, as an unexplained fact, that they do produce changes in other bodies.