many proofs to show that the neglect of mental cultivation may lead to an impaired state of cerebral nutrition; or, on the other hand, that diseased action of the brain may injure or destroy the powers of the mind. These are fundamental truths of vast importance to the student of mental pathology as well as of physiology. It may be readily understood that mental and physical development should go hand in hand together, and mutually assist each other; but we are not, therefore, authorized to conclude that mental action results from the physical working of the brain. The strings of the harp, set in motion by a skilful performer, will produce harmonious music if they have been previously duly attuned. But if the instrument be out of order, although the player strike the same notes, and evince equal skill in the movements of his fingers, nothing but the harshest discord will ensue. As, then, sweet melody results from skilful playing on a well-tuned instrument of good construction, so a sound mind, and a brain of good development and quality, are the necessary conditions of healthy and vigorous mental action."

They here take the fact that neglect of mental cultivation may lead to an impaired state of cerebral nutrition -that idleness of mind may lead to weakness of brain -as a proof of the independence of mind and its cooperation with the brain! To show how complete a fallacy this is, we have only to consider a case precisely parallel. Sensibility is a property of the nervous tissue, a special property depending on the speciality of the tissue, in precisely the same sense as Contractility is a property of the muscular tissue. We call the collective manifestations of the one, Mind; we call some of the other, Strength. Now let the passage just quoted be brought in juxtaposition with the following:

That Strength has an existence independent of mere blind weak Matter, will be evident to the experience of every thoughtful person. Strength, therefore, must be

accepted as an "immaterial principle," using the muscles as its instruments. Strength plays upon the muscles as a musician on the harpsichord. We have innumerable proofs that neglect of the exercise of this Strength leads to an impaired state of muscular nutrition, so that a man who does not employ his Strength will be found to have small and flaccid muscles; while on the other hand-a —as a further proof that Strength is independent of muscular fibre-any disease of the fibre will derange or totally destroy the powers of the muscle-as snapping the strings of a harpsichord will destroy its musical capacity! True indeed it is that physical Strength and muscular development go hand in hand, but we are not to conclude therefrom that Strength is dependent on the physical condition of the muscles!

Instead of such absurdity and confusion, let us calmly recognize what observation tells us, viz., that Sensibility is the special property of a special tissue, a mystery as inscrutable as that of gravitation or chemical affinity.* We shall thus escape the coarse hypotheses of Materialists and the absurd logic of Immaterialists.

*This subject is recurred to further on, p. 214.

SECTION XX.

VITAL DYNAMICS: INSTINCT AND INTELLIGENCE.

THE study of Animal Life starts, as we have seen, from the localization of the two capital properties-Contractility and Sensibility-in two fundamental tissues— the muscular and nervous. How little this fundamental position is understood by the majority of Biologists may be gathered from the fact, that while most of Bichat's successors have believed Contractility to be a property of all the tissues, differing only in degrees of intensity, even the writers of the present day are divided on the question. In the last edition of Quain's Anatomy, the editors modified their opinion during the progress of the work through the press; at first inclining to the belief that contractility had been observed where no muscular fibres could be traced, and only giving up that opinion in obedience to more recent and conclusive experiments. That Contractility is the special property of a special tissue is the final result of the most recent investigations. The reader is referred to Longet's Traité de Physiologie, and to Todd and Bowman's Physiological Anatomy, for ample evidence; meanwhile here is one important fact: Muscular tissue is composed of Fibrine, and Fibrine in the blood, immediately after coagulation, manifests contractility.

The Positive nature of this conception will be better appreciated by seeing how even so excellent a physiologist as Dr. Carpenter, while virtually accepting it, nevertheless wanders into the Metaphysical path, and gives a vague expression where precision was so needful. "Various attempts," he says, "have been made

to show that the contraction of Muscle is an electrical phenomenon; but no proof has been given that such is the case; and every probability seems to be in favour of its being one of the manifestations of the Vital Force." What business this mysterious entity, Vital Force, has here, only a Metaphysician could imagine. The positive thinker, using the term Vital Force as the generalized expression of all the properties of organic beings, must conclude, that it is reasoning in a circle to call contractility "one of the manifestations of the Vital Force;" whereas, by calling it the special property of a special tissue, he does no more than record observed facts; and should at any future time contractility be resolved into an electrical phenomenon, the discovery will leave the speciality unaltered, since the special manifestation of electricity, known as muscular contraction, will always remain associated with a special tissue known as the muscular tissue.

It may be said, therefore, that in the perfect correspondence of the two ideas of Tissue and Property, a positive basis is given to Biology.

We are as yet but on the threshold of this science. The minute researches of thousands of inquirers are still necessary before some of the most capital problems can be solved; but the whole history of science tells us with what accelerated rapidity discoveries are made when once the right Method is thoroughly followed. Nature answers if we but know how to question. Her treasures are open if we know where to look.

Motion and Sensation are the two capital functions of Animal Life. We have only to consider either of them a moment to be aware of the immensity of work still to be done before these processes are reduced to scientific law. Of Muscular actions, for example, some are notoriously voluntary, some involuntary. This broad distinction is as perceptible as the distinction between a Plant and an Animal. But as, on closer in

spection, it is difficult to draw the lines of demarcation between plants and animals, so, also, is it to ascertain precisely what actions are voluntary, and what involuntary. To take a striking example: when you hurt a frog's foot, and the frog leaps away, and leaps as often as you irritate it, does not this seem clearly a case of voluntary action? It is not, however-at least not always, if ever; it is no more voluntary than your winking when a hand is passed rapidly before your eyes. You must accept this paradoxical assertion; for to prove it would require an examination of the nervous system quite beyond present limits.

Not only are the voluntary actions difficult to be demarcated from the involuntary, but there arises a further complication, inasmuch as actions which, in early life, are perfectly beyond control of the will, become afterwards so completely controllable, within certain limits, as to deserve the name of voluntary. The excretory actions, for example, are, in infancy and certain diseases, wholly involuntary; yet, by the influence of habitual resolution, they become voluntary actions. On the other hand, Dr. Carpenter luminously explains what, after Hartley, he calls "secondary automatic actions," viz., those actions which were at first performed voluntarily, requiring a distinct effort of the will for each, and become, by repetition, so far independent of the will, that they are performed when the whole attention of the mind is bestowed elsewhere.

Besides those actions which are automatic or involuntary, there is a class of actions I should be disposed to further distinguish as Organic, under which would range the Instinctive. Who that has watched mothers with their children, has not been struck with the remarkable sameness of their deportment, even to their very tricks and caresses? Who has not noticed how all children play alike? They use the same muscular varieties, throw themselves into the same complicated postures,