The Poetry of Science; or, Studies of the Physical Phenomena of Nature

by Robert Hunt

Animal and vegetable diet, which is composed largely of carbon and hydrogen, passes into the digestive system, and becomes converted into the various matters required for the support of the animal structure. The blood is the principal fluid employed in distributing over the system the necessary elements of health and vigour, and for restoring the waste of the body. This fluid, in passing through the lungs, undergoes a very remarkable change, and not merely assumes a different colour, but really acquires new properties, from its exposure to the air with which the cells of these organs are filled. By a true chemical process, the oxygen is separated from the air, that oxygen is made to combine with the carbon and hydrogen, and carbonic acid and water are formed. These are liberated and thrown off from the body either through the lungs or by the skin. In the processes of life, as far as we are enabled to trace them, we see actions going on which are referred to certain causes which we appear to explain. Thus, the combination of the oxygen of the air with the carbon of the blood is truly designated a case of chemical affinity; and we find that in endeavouring to imitate the processes of nature in the laboratory, we are, to a certain extent, successful. We can combine carbon and oxygen to produce carbonic acid; and we know that the result of that combination is the development of certain definite quantities of heat. Let us examine the conditions of this chemical phenomenon, and we shall find that in the natural and artificial processes,—for we must be allowed to make that distinction,—there are analogous circumstances. If we place a piece of pure carbon, a lump of charcoal or a diamond, in a vessel of air, or even of pure oxygen gas, no change will take place in either of these elements, and, however long they may be kept together, they will still be found as carbon or diamond, and oxygen gas. If we apply heat to the carbon until it becomes incandescent, it immediately begins to combine with the oxygen gas,—it burns;—after a little time all the carbon has disappeared, and we shall find, if the experiment has been properly made, that a gas is left behind which is distinguished by properties in every respect the reverse of those of oxygen, supporting neither life nor combustion, whereas oxygen gives increased vigour to both. We have now, indeed, carbonic acid gas formed by the union of the two principles.

A dead mass of animal matter may be placed in oxygen gas, and, unless some peculiar conditions are in some way brought about, no change will take place; but, if it were possible to apply the spark of life to it, as we light up the spark in the other case, or if, as that is beyond the power of man, we substitute a living creature, a combination between the carbon of the animal and the gas will immediately begin, and carbonic acid will be formed by the waste of animal matter, as in the other case it is by the destruction of the carbon; and, if there is not a fresh supply given, the animal must die, from the exhaustion of its fabric. Now, in both these cases, it is clear that, although this chemical union is a proximate cause of heat, there must be existing some power superior to it, as the ultimate cause thereof.

The slow combustion (eremacausis) of vegetable matter, decomposing under the influence of moisture and the air, does not present similar conditions to those of the human body, although it has been insisted upon to be in every respect analogous. That the results resemble each other is true, but we must carefully distinguish between effects and causes; and the results of chemical decomposition in inert matter differ from those in the living organism. The vegetable matter has lost the principle of organic life, and, that gone, the tendency of all things being to be resolved into their most simple forms, a disunion of the elements commences: oxygen, hydrogen, and carbon pass off either in the gaseous state or as water, whilst some carbon is liberated in a very finely-divided condition, and enters slowly into combination with oxygen supplied by the water or the air. Hydrogenous compounds are at the same time formed, and, under all these circumstances, as in all other chemical phenomena, an alteration of temperature results. Heat results from the chemical changes, and eventually true combustion begins.

The animal tissue may act in the same way as platina has already been shown to act in producing combination between gases; but of this we have no proof. We know that electricity is capable of producing the required conditions, and we also learn, from the beautiful researches of Faraday, that the quantity of electricity developed during decomposition is exactly equal to that required to effect the combination of the same elements. Thus it is quite clear that, during the combination of the carbon of the blood with the oxygen of the air, a large amount of electricity must become latent in the compound. The source of this we know not: it may be derived from some secret spring within the living structure, or it may be gathered from the matter surrounding it. There is much in nervous excitation which appears like electrical phenomena, and attempts have been frequently made to refer sensation to the agency of electricity. But these are the dreams of the ingenious, for which there is but little waking reality.

Every mechanical movement of the body occasions the development of heat; every exertion of the muscles produces sensible warmth; and, indeed, it can be shown by experiment that every expansion of muscular fibre is attended with the escape of caloric, and its contraction with the absorption of it. There are few operations of the mind which do not excite the latent caloric of the body, and frequently we find it manifested in a very remarkable manner by a suddenly-awakened feeling. The poet, in the pleasure of creation, glows with the ardour of his mind, and the blush of the innocent is but the exhibition of the phenomenon under some nervous excitation, produced by a spirit-disturbing thought. Thus we see that the processes of digestion and respiration are not the only sources of animal heat, but that many others exist to which much of the natural temperature of the body must be referred.

So much that is mysterious belongs to the phenomena of life, that superstition has had a wide scope for the exercise of its influence; and through all ages a powerful party of mankind have imagined that the spirit of human curiosity must be checked before it advances to remove the veil from any physiological causes. Hence it is that even at the present day so much that stands between what, in our ignorance, we call the real and the supernatural, remains uninvestigated. Even those men whose minds are sceptical upon any development of the truths of great natural phenomena,—who, at all events, will have proof before they admit the evidence, are ready to give credit to the grossest absurdities which may be palmed upon them by ingenious charlatans, where the subject is man and his relations to the spiritual world.

Man, and the races of animals by which he is surrounded, present a very striking group, consider them in whatever light we please. The gradual improvement of organic form, and the consequent increase of sensibility, and eventually the development of reason, are the grandest feature of animated creation.

The conditions as to number even of the various classes are not the least remarkable phenomena of life. In the lowest orders of animals, creatures of imperfect organization,—consequently those to whom the conditions of pain must be nearly unknown,—increase by countless myriads. Of the infusoria and other beings, entire mountains have been formed, although microscopes of the highest powers are required to detect an individual. Higher in the scale, even among insects, the same remarkable conditions of increase are observed. Some silkworms lay from 1,000 to 2,000 eggs; the wasp deposits 3,000; the ant from 4,000 to 5,000. The queen bee lays between 5,000 and 6,000 eggs according to Burmeister; but Kirby and Spence state that in one season the number may amount to 40,000 or 50,000. But, above all, the white ant (Termes fatalis) produces 86,400 eggs each day, which, continuing for a lunar month, gives the astonishing number of 2,419,200, a number far exceeding that produced by any known animal.

These may appear like the statements in which a fictionist might indulge, but they are the sober truths discovered by the most pains-taking and cautious observers. And it is necessary that such conditions should prevail. These insects, and all the lower tribes of the animal kingdom, furnish food for the more elevated races. Thousands are born in an hour, and millions upon millions perish in a day. For the support of organic life, like matter is required; and we find that the creatures who are destined to become the prey of others are so constituted that they pass from life with a perfect unconsciousness of suffering. As the animal creation advances in size and strength, their increase becomes limited; and thus they are prevented from maintaining by numbers that dominion over the world which they would be enabled from their powers to do, were their bands more numerous than we now find them.

The comparative strength, too, of the insect tribes has ever been a subject of wonder and of admiration to the naturalist. The strength of these minute creatures is enormous; their muscular power, in relation to their size, far exceeds that of any other animal. The grasshopper will spring two hundred times the length of its own body. The dragonfly, by its strength of wing, will sustain itself in the air for a long summer day with unabated speed. The house-fly makes six hundred strokes with its wings, which will carry it five feet, every second. The stag-beetle, were it the size of the elephant, would be able to tear up the largest mountains.