Modern science, in dispelling those antiquated notions, has now assigned to the spleen a very important part in our internal mechanism. The part it plays may be thus described. The blood, as every one who has looked at a thin film of that substance through a microscope will know, is in reality a fluid as clear as water, and derives its colour from the immense number of little red bodies the ‘corpuscles,’ which float in it. These red corpuscles of human blood do not attain a greater size than the 1/3500th part of an inch—that is, three thousand five hundred of these little bodies placed in a line would make up an inch in length. In addition to the red bodies, there exist in the blood a much smaller number of ‘white corpuscles,’ each containing a little central particle which the red ones want. From the results of the most recent researches it would appear that the red corpuscles are produced by the partial destruction of the white ones; and that the little central particles of the white globules, when coloured, appear before us as the red corpuscles of the blood. Now the spleen is to be regarded as the great manufactory or depôt in which the red corpuscles are thus produced from the white ones, and in which also many of the white corpuscles are themselves developed. And it would also appear highly probable, that when the red globules of the blood have served their turn in the economy of the body they are broken down in the spleen; their material being doubtless used for some wise purpose in the maintenance of our complicated frame.
A very common idea, but one founded on no certain or feasible grounds, is that which maintains that our bodies undergo a complete change and renewal of all their parts every seven years. The ‘mystical’ nature of the number seven, has had an unquestionable effect in originating this opinion; and although the age of fourteen and again that of twenty-one may be regarded as marking the attainment of youth and manhood or womanhood respectively, yet physiology gives no countenance to the popular opinion that of necessity these periods are those of sweeping bodily change. On the contrary, it might be shewn that the periods at which full growth of body is attained vary with climate, race, and constitution—that is, with the personal nature, and with the physical surroundings of individuals, communities, and nations. The true state of matters as disclosed by physiology, leads us to contemplate actions and changes which are of infinitely more wondrous kind than those involved in the idea of septennial change. For if there is one axiom which physiology maintains more constantly than another, it is that which teaches that constant and never-ceasing change is the lot of life from its beginning to its end.
No part of the body of a living being is free from these changes of substance, through which indeed every act of life is carried on. Every movement of a muscle—the winking of an eyelid or the lifting of a finger—implies waste of the organs and parts which move. The thinking of a thought implies wear and tear of the organ which thinks—the brain itself. Were it possible to spend existence even in a perfectly still and rigid condition, there are still actions to be performed which are necessary for the maintenance of life, and which necessitate continual waste and wear of the tissues. Thus the beating of the heart, the movements of our chest in breathing, and the very act of receiving and digesting food—actions which are in themselves concerned with the repair of the frame—can only be performed through the intervention of processes of work, and waste of body. So that a living being is to be regarded as passing its existence in a constant state of change. Its particles are being continually wasted, and as incessantly renewed; and although the growth of our bodies may be said to culminate at various periods of our life, yet it is anything but correct to say that there are marked epochs of change in human existence. The truth is that change and alteration are our continual heritage; and it is strange indeed to think that not an organ or part of our bodies exists which has not repeatedly in its history been insensibly and gradually, but none the less perfectly, renewed in all its parts. Our particles and substance are being dissipated in very many ways and fashions. Chemically and physically, we are in a state of continual break-down; whilst on the other hand, it may be shewn that the forces of life are enlisted powerfully on the side of renewal and repair.
In connection with the exercise of our senses there are not a few points on which popular ideas stand in need of correction. When we speak of ‘seeing’ or ‘hearing,’ the exercise of these or any other of our senses indeed, is usually referred to the organ concerned—eye, ear, nose, or tongue, as the case may be. A little consideration, however, will shew us that we make a very grievous mistake in referring the act of sensation or perception to the organ itself. Let us consider for a moment what happens when we acquire ideas regarding the form of an object through the sense of touch. We may in the first place ‘will’ to touch the object in question; the act of ‘volition’ as it is termed, originating in the brain, being transformed into nerve-force, and being further directed along the particular nerves which supply the muscles of one finger or along those which supply all the fingers. The muscles are thus stimulated to action, and through their agency the fingers are brought into contact with the desired object. Leaving the sense of sight out of consideration for a moment, we know that we can through the sense of touch gain ideas regarding the form, size, hardness, and other qualities of the object. Our nervous system is thus bringing us into relation with the outer world and specially with that portion of it represented by the object we have touched. But how have we gained our knowledge? The reply to this question leads us at once to perceive that the tips of the fingers do not represent the seat of knowledge. And a further consideration makes it equally clear that the brain must be credited not only with the task of perceiving, but also with that of appreciating what has been perceived. Hence we are forced to conclude that just as the first nervous impulse shot through the nerves to the fingers, so a second impulse has passed from the fingers to the brain. Our sense of touch has given origin to a subtle force which has passed upwards to the brain, and has there become transformed, through a mechanism—of the working of which we know as yet absolutely nothing—into perception and thought. Similarly with the work of the eye, of the ear, and of other senses.
When we talk of seeing or hearing, we are in reality speaking of the act of the brain, not of the eye or ear, which are merely the ‘gateways’ through which the brain obtains its knowledge. And that the brain is the true seat of the senses, may be proved to us from the side of pathology—the science which makes us acquainted with the causes and nature of disease. Cases are well known in which injury of the brain as the seat of sense has given origin to depraved sensations. Post-mortem examinations of persons who were continually conscious of a disagreeable odour have proved that these persons had laboured under brain-disease; whilst one case is on record in which, after a fall from a horse, and for several years before his death, a person believed that he smelt a bad odour. So also the sense of sight may be altered from internal causes, and on this ground may be explained the real nature of many cases of so-called ghost-seeing and spectral illusions. One well-known case, in illustration of this latter point, was that of Nicolai, a Berlin bookseller, who, neglecting to be bled in accordance with his usual custom, began to see strange persons in his room, and faithfully described the appearance of the figures. The figures disappeared when he had been bled once more. Thus in all such cases we must believe that those parts of the eye or ear which would have been concerned in seeing the supposititious objects or hearing the supposititious sounds—had either existed—were irritated from the brain and produced the delusive sensations. Thus the common phrase that ‘seeing is believing’ is in one sense literally true; for the act of sight apparently exercised in the person who suffers from optical illusions is in reality performed by the brain and is thus an act of belief, even if it be one of unconscious kind. The entire subject of physiological errors teems with valuable applications, but with none more practical or worthy of remark than that which would insist on the advantages, in the ruling wisely of our lives, to be derived from even an elementary acquaintance—such as should be included in the curriculum of every school—with the science of life.
MR ASLATT’S WARD.
IN FOUR CHAPTERS.—CHAPTER II.
I did not then know what I afterwards learned, the full extent of her obligations to Mr Aslatt, nor the sentiments of love which that gentleman came to entertain for his beautiful ward. A pretty child of six, singing in the streets of a foreign city, she had first attracted his notice; and her sad lot had so touched his heart, that he could not rest till he had rescued her from it. The itinerant musicians in whose company he found her spoke of her as an orphan, the child of a former comrade, and made no objection when Mr Aslatt proposed to adopt her and provide for her future. He was a lonely man, with no near relatives to resent this action on his part; and the child became the delight of his life and the idol of his heart. He was but a young man when he took the little orphan under his protection, and his friends thought it an alarming proof of the eccentricity which had already marked him. But a bitter disappointment had blighted his life, and made it impossible, he then thought, for him ever to have a happy married life, such as he had once anticipated. He determined to spend his wealth in giving brightness to the existence of the little fairy-like creature, who seemed made to live in the sunshine; and in the effort to promote little Rose’s happiness he found his own. When it was that his paternal fondness for her passed into a warmer more passionate emotion, and he experienced a longing to bind her to himself by the closest of all ties, I could not know; but that such was the nature of his regard for her when I went to reside at his house, was beyond doubt.
And it was equally plain that Rose entertained for him a very different feeling. She looked upon him as her dear guardian and friend, one who had been as a father to her; but I do not think the possibility of any other relationship had ever crossed her mind. Indeed it was pretty evident to me that another was frequently in her thoughts to the exclusion of Mr Aslatt, who was so untiring in his efforts to win her love. I was grieved to see how often she wounded him by her thoughtless wilful conduct; and the patience with which he bore with her capricious moods, fully enlisted my sympathies on his behalf. If any word of mine could have influenced my wayward charge to value more highly her true-hearted friend, it would have been spoken; but from what I knew of her, I judged that I should better serve Mr Aslatt’s cause by silence than by speech.