to understand why the language which is applicable to any one term of the series may not be used to any of the others. We think fit to call different kinds of matter carbon, oxygen, hydrogen, and nitrogen, and to speak of the various powers and activities of these substances as the properties of the matter of which they are composed. When hydrogen and oxygen are mixed in a certain proportion, and the electric spark is passed through them, they disappear, and a quantity of water, equal in weight to the sum of their weights, appears in their place. There is not the slightest parity between the passive and active powers of the water and those of the oxygen and hydrogen which have given rise to it.

Nevertheless, we do not hesitate to believe that, in some way or another, the properties of the water result from the properties of the component elements of the water. We do not assume that a something called aquosity entered into and took possession of the oxide of hydrogen as soon as it was formed, and then guided the aqueous particles to their places in the facets of the crystal, or amongst the leaflets of the hoar-frost.

Does anybody quite comprehend the modus operandi of an electric spark, which traverses a mixture of oxygen and hydrogen? What justification is there, then, for the assumption of the existence in the living matter of a something which has no

representative or correlative in the not living matter which gave rise to it? What better philosophical status has 'vitality' than 'aquosity?' And why should 'vitality' hope for a better fate than the other 'itys' which have disappeared since Martinus Scriblerus accounted for the operation of the meat-jack by its inherent 'meat-roasting quality,' and scorned the materialism of those who explained the turning of the spit by a certain mechanism worked by the draught of the chimney."

The mere chemical analysis of inorganic bodies, then, proves that as to substance or matter they are identical with inorganic objects. But science, it is contended, carries us much farther, not merely inferentially from this unity of composition, but directly by demonstrating that what is called vital force is simply mechanical and chemical force transformed through the special conditions under which it acts. The human body is as incapable of generating force as is a steam-engine or a galvanic battery. It only distributes the force which it receives from the world without, and varies its manifestations to the senses. Its every action and process-walking and climbing, pulling and pushing, respiration and digestion, assimilation and excretion can be shown to be either a mechanical or chemical operation. The force displayed by animals in muscular contractions is entirely derived from the energy stored up in the

food which they consume. The heat which is diffused through their frames is due to chemical combination. Digestion is simply a form of combustion. The circulation of the blood is indubitably a mechanical movement effected by mechanical force. What room is left in organisms for a vital force essentially distinct from the inorganic powers of matter? It is unnecessary to dwell longer on an argument which has been so often presented to the English public in the brilliant expositions of Professor Tyndall.

The significance of the doctrine of evolution must also not be overlooked in the present connection. A few years ago every group of organisms called a species was supposed to have originated in a direct creative act or miracle. Now, this hypothesis is almost universally abandoned. Its place is occupied by Darwinianism or some other form of the development theory. An enormous mass of facts has been collected from astronomy, geology, geography, biology, linguistics, &c., and presented in a light which has convinced most scientific men that from a few organic forms, if not from a single organism, of the simplest kind, all organised beings have been gradually, naturally, and necessarily formed and distributed. But if this theory be true (and those who deny its truth must disprove it), obviously the probability is very great that, as there has been no

supernatural interposition in the course of the evolution of organic beings, so there was none when life and organisation first began to be, and consequently, that no absolutely new principle, no immaterial vital force, was then abruptly and inexplicably inserted into nature.

If it be admitted, on the strength of the foregoing and similar considerations, that even a single vital cell may have originated in the laboratory of nature, under peculiar conditions, from the combination of inorganic elements and the action of chemical and mechanical forces, it can be left to the Darwinian theory of development to explain how that single cell might, in the course of millions on millions of years, by successive infinitesimally minute modifications, be the source from which every plant and animal in the world has derived its life and organisation. In so far as biology accomplishes, or attempts to accomplish, this task, it may be held to be simply a stage or section of the materialistic theory, and materialism to be identical with biological science.

It will be said that there is an impassable barrier between vegetable and animal life-that plants can never have risen into animals, nor animals degenerated into plants. Mr Spencer has thus answered this argument when replying to Dr Martineau: "This is an extremely unfortunate objection to raise. For though there are no

transitions from vegetal to animal life at the places Mr Martineau names (where, indeed, no biologist would look for them), yet the connection between the two great kingdoms of living things is so complete that separation is now regarded as impossible. For a long time naturalists endeavoured to frame definitions such as would, the one include all plants and exclude all animals, and the other include all animals and exclude all plants. But they have been so repeatedly foiled in the attempt that they have given it up. There is not chemical distinction that holds; there is no structural distinction that holds; there is no functional distinction that holds; there is no distinction as to mode of existence that holds. Large groups of the simpler animals contain chlorophyll, and decompose carbonic acid under the influence of light, as plants do. Large groups of the simpler animals, as you may observe in the diatoms from any stagnant pool, are as actively locomotive as the minute creatures classed as animals seen along with them. Nay, among these lowest types of living things it is common for the life to be now predominantly animal, and presently to become predominantly vegetal. The very name zoospores, given to germs of Alge, which for a while swim about actively by means of cilia, and presently settling down grow into plant-forms, is given because of this conspicuous community of nature. So complete