Herbert George Flaxman Spurrell

“ It is, of course, the ambition of the physiologist to make protoplasm, but so far he has got no further than making some of the complicated bodies into which protoplasm breaks up when it dies. A little while ago this bare possibility was loudly derided, but the advance in organic chemistry has been so great of late years, and so many complicated substances which once seemed as unobtainable as protoplasm itself have been made in the laboratory, that we now have hope of a precise knowledge of the chemistry of life some day, though that day may be yet very distant. ”

“ Turning to the physical side of physiology, it is unnecessary here to say more about the means employed for studying the properties of muscle and nerve than that many of the phenomena occur with such extreme rapidity that they can only be perceived by the photographic plate. In the study of the large organs, the physiologist finds a fascinating employment in devising models in which, so far as possible, all the physical conditions are reproduced, and this not only for the benefit of his pupils, but to help himself in perceiving their meaning. ”

“ In physiology the publication of the various steps is sometimes withheld until the objective has been reached, but our knowledge of life is like Solomon’s temple: a David collects the material, and his successor raises the edifice. The world watches it grow. ”

“ While the physiologist is quietly working, making slow but sure progress, his critics, friendly and otherwise, buzz about him like bees. There are some who are in a chronic state of excitement, expecting a revolutionizing discovery from hour to hour; there are others who assure him that he has reached the limit of human powers of comprehension, and can never know much more than he does to-day ”

“ In the first place, regarding protoplasm as a chemical structure, why, if kept under favourable conditions, should it ever break down? We have no reason to suppose that it need. It is hard to see how the minute animals, consisting of only one cell, can die of old age, provided that no injurious influence be brought to bear upon them. When an individual has grown to a certain size, it divides in two, and each enters upon life afresh. Why, therefore, should not all the cells of the body continue to renew their youth? ”

“ The loss of some organs will bring death only after a considerable time, while the failure of others disturbs its economy fatally, and causes an almost immediate cessation of the vital functions. Any interference with the normal conditions of the brain, heart, or lungs is very dangerous, and it is injury or disease of one of the three which puts an end to most men’s troubles. If the brain weakens so that it no longer keeps the heart beating or the muscles, which fill and empty the lungs, to their duties, the body, for obvious reasons, can no longer keep up the cycle of changes we call life. ”

“ A pleasant contrast is the athlete. The athlete is a man who endeavours to develop the latent powers of his body to the utmost; and in the achievement of this desirable object the physiologist takes great interest. Physiology has revolutionized our ideas of training, as well as many other things, during the last half-century. We now recognise two kinds of training—the preparation which a healthy man makes for an occasion on which unusual exertions will be expected of him, and the slower and permanent strengthening of the whole body, now usually called physical culture. ”

“ As, moreover, our humble ancestors, the fishes, move literally mouth foremost, it is not surprising to find the organs of space perception, the eyes, also situated in its neighbourhood, especially when one considers that their food is often of a lively character, and requires precision of movement to secure it. The inevitable consequence of thus grouping the more important organs of perception under the fore-end of the neural canal is that it grows and develops more highly here than elsewhere along its length, and soon is in a position to dictate to the rest of the body. ”

“ I do not, of course, say that a man must develop equally both his body and mind; only, that the former must be functionally competent. The absurdity of supposing that [100] the brain can benefit by forming part of an unhealthy body is, surely, obvious to all. Determined invalids may produce splendid work, as Darwin did, in spite of ill-health, but not because of it, and men of great mental energy will sometimes wear themselves out prematurely by their restlessness; but starvation and maltreatment of the body will not create intellect, however morbidly it may stimulate the imagination. ”

“ All the cells in the body rest at times; even the cells of the heart, carefully as they are nourished and incessant as their work seems, rest between each beat, and the cells of the nervous system form no exception. The brain no less than the body requires periodic rests to renew its chemical stores, and these rests have to be all the longer, as during the waking hours the brain works harder and less intermittently than any other organ. It is only because the brain is the seat of consciousness and the source of voluntary movements that these phenomena are suspended during sleep. ”

“ To say, however, that an animal’s body consists of cells is to take an entirely wrong starting-point. A cell is complete in itself, and can live if properly fed, even though separated from its neighbours. Many whole animals consist of only one cell. A cell is, moreover, capable of growing and dividing, thus giving rise to two cells with two nuclei, and it is only because cells find that it pays better not to separate, but to form masses and specialize at different kinds of work, that we have large animals composed of millions of cells like ourselves. ”

“ The chemistry of the living cells—their anabolism, or how fresh material is built into their structure; their katabolism, or how the same structure is broken down that work may be done; in fact, the general metabolism—is so complicated, and so little understood as yet, and requires so extensive a knowledge of chemistry to follow, that it is best left alone by people who do not want to go into it deeply. ”

“ Having now roughly sketched out the scheme upon which such a body works, we can go on to a more detailed examination of the division of the labour, and the way in which each department supplies, and is dependent upon, the others. If we were to do this thoroughly, it would take a great deal of time and space, for the physiology of a potato plant, though essentially the same, presents many differences from that of a horse; but the physiology of the great human interest is also that of the most complicated animal, namely, man, so it is on him that we shall focus our attention. ”

“ Yet by strength alone no athlete can excel; success depends upon skill. He must have the strength to work with, but he must have the knowledge to apply it without wasting energy, and the ability to do this with precision. He must practise well the sport he intends to adopt—in other words, train his central nervous system.
Here, again, we must hark back to the main idea—the unity of the body. We have already dealt in this essay with the bodily needs in the way of food and exercise, and we must now consider the needs of its nervous components. ”

“ All the substances used as food, found in or excreted by the body, are being thoroughly studied; but it should be remembered that this is chemistry, not physiology. Physiology is only concerned with protoplasm, and the [110] physiologist who goes deeply into the chemistry of non-living matter has to discipline his mind against forgetting its ceaseless change, and trying to regard it as though it were constant. The actual chemistry of protoplasm will be a very hard nut to crack, and may defy us until we can depict molecules as well actually as we now can symbolically. ”

“ In the fore-brain there are centres for specially governing all the motor organs; but by a strange arrangement the main root of the brain is overwhelmed by its own offshoot, the hemisphere, or lobe which gives rise to the olfactory bud. In fact, so great is the importance of the sense of smell to an animal whose one object in life is to find food, that, instead of the hemisphere being subordinate to its parent, it seems to take over most of the latter’s business, receiving a report of the sensations collected by it, and sending out orders upon its own initiative. ”

“ Everyone knows the doctor, and everyone knows that physiology deals with the ‘functions of different organs of the body’; but the public rarely meet the physiologist, except in the fanciful caricatures of his enemies, which though frequently personal are rarely accurate. ”

“ We have seen how energy is released in the body from chemical compounds, and made use of by the body. So now, after a moment’s thought, it must be plain that every stimulus which goes to the brain must have its effect there, and that a man’s thoughts and conduct are entirely dependent on what has, at some time or other, come in from the external world. The association centres can evolve wonderful thoughts, but they are structurally derived from the grosser sense organs, and must get all the material they work upon from them. ”

“ In Essay II., which dealt with the chemistry of the body, we said that if we were only to live upon meat we [96] should tax our digestive apparatus severely by having to eat more proteid than we required in order to get enough carbon. The converse, however, is equally true: if we fed only upon vegetables, we should again have to over-eat. Plants most of them contain large stores of carbohydrate; potatoes and rice are rich in starch, onions in sugar; but an exclusively vegetarian diet would necessitate our consuming huge quantities, as its proteid-supply is bad. ”

“ In using the word ‘unscientific’ I imply, of course, no reproach. I mean simply to denote those people who have specialized in some branch of knowledge other than those collectively known as Natural Science. ”

“ We can, to a certain extent, regulate the depth and frequency of our breathing, and we can blink our eyes voluntarily; but an average man would be quite at a loss what to do if asked to make the pupil of his eye dilate and contract, the glands of his stomach secrete, or his heart alter its rhythm.
It is a familiar fact that some reflex actions can be altered by an effort of the will; in other words, an impulse from a brain cell will prevent a nerve cell in the spinal cord from discharging. ”

“ Oxygen is required by the body pure, and, as it is uncombined with anything in the air, it needs no digestion to free it. A special organ, however, is necessary to absorb it. This is the lung. The lungs originate, just like a gland, by a pouching of the alimentary canal near its origin, but differ from a gland in their cells being very much flattened, to offer a large surface to the air on one side and to the bloodvessels on the other. Incessantly during life air is being drawn into the lungs; that the cells to which it is there exposed may transfer its oxygen to the blood ”

“ As, moreover, the first thing which a cell does when it grows is to divide, the whole proceeding looks rather futile. But ready-made protoplasm of an assimilable shape is rare, and it is not often that a cell, unless it be a plant or a parasite, finds itself in a substance which can be handed straight to the nucleus without further elaboration. Usually the cell has to discharge from itself a reagent, which will develop the right chemical qualities in the matter it wants to absorb. This substance is known as an enzyme, or ferment. ”

“ In cooking, parasitic animals which are strong enough to survive the ordeal by acid in the stomach are killed, and the food itself is made more accessible, the indigestible cellulose envelopes of the vegetable cells being burst open, and the collagen of the connective tissues converted into gelatin.
No less important than the quality of our food is the quantity; and here, again, we get a good illustration of the necessity for regarding the body as a whole. A healthy man’s appetite is his best guide, and if he follows it he cannot go far wrong. ”

“ Of these, carbon and oxygen unite, in certain proportions and under certain conditions, to give rise to carbonic acid; hydrogen and oxygen produce water; nitrogen and hydrogen give rise to ammonia. These new compounds, like the elementary bodies of which they are composed, are lifeless. But when they are brought together under certain conditions they give rise to the still more complex body, protoplasm, and this protoplasm exhibits the phenomena of life.’
Until we have further knowledge of the changes which constitute these phenomena, physiology must remain descriptive rather than explanatory. ”

“ A man requires, as we have described before, air and food. The air must contain the proper amount of oxygen, and the food must consist of liquids and solids.
The important liquid is water. More than half by weight of the whole body is water, and we are always losing it: through the skin, through the lungs, and through the kidneys. People may drink alcohol with water, but not instead of it. Indeed, the more alcohol they take, the more water they require, for if they take their spirits in an undiluted form, they take water out of the body. ”

“ If it were possible to live without work, i.e., without movement of any kind, it might be; but to do work, more carbon must be oxidized than the proteid molecule contains.
Carbon, the next item on our list, is familiar to everyone in the comparatively pure form of coal, charcoal, and the ‘lead’ of pencils. It is commonly used to burn—i.e., oxidize—that heat may be obtained to boil water and to work machinery. This is precisely what it is required to do in the body, where it is burnt by oxygen taken in by the lungs, that heat and energy may result. ”

“ That of the liver is largely excretion or refuse from the blood without direct action on the food, but it enables the pancreatic juice to do its work by making the food again alkaline, and stimulates the muscular coats of the intestine to force its contents along. That of the pancreas is the most important digestive fluid in the body, containing many ferments; it acts alike on proteids, carbohydrates, and fats—in fact, digests everything—so that the rest of the long tube is freed from any more laborious duty than absorbing them as they pass. ”

“ The body can help to give rise to new bodies, but its own tissues must wear out, and when the colony of cells is exhausted it must die. Careful diet and regular habits, the minimum of wear and tear, may enable the body to run its full term; but they cannot lengthen the lease of life.
So far only can the physiologist take us. Physiology may teach us how to develop our powers and economize our strength; it is already beginning to convert medicine from an art into a science ”

“ Our task, however, is simplified by our having only man to consider; and although most of the higher animals are so much alike that they might be considered in general and contrasted in detail, it is a great thing to get rid of the whole vegetable kingdom with bacteria and parasitic animals.
One of the first requisites for the maintenance of life, as was mentioned above, is nitrogen. Now, nitrogen is one of the commonest elements in the world, but it is the hardest to supply to the body. Four-fifths of the air is pure nitrogen, but pure nitrogen is useless as a food. ”

“ A little piece of the cortex becomes diseased and hyperexcitable. The sufferer suddenly becomes acutely conscious of one of his members—a hand or a foot, say—not because there is anything the matter with it, but because the corresponding area in the brain is morbidly active, and he refers the sensation to the part from which it receives its nerves. The next moment the limb begins to twitch, and the excitement spreading, as in the experiment we described above, to other centres which are not diseased, they, too, become [90] morbidly active, and the whole body is thrown into convulsions. ”

“ In the third essay in this volume we saw that the flow of the lymph and the blood in the veins is largely dependent upon the movements of the limbs. Muscular exercise, therefore, must be taken to prevent the circulating streams from growing sluggish. Obviously, many evils must arise if they do so. Not only would the muscles be starved by the slowness with which they received their food, but they would also be poisoned by the slowness with which the products of their own metabolism were removed. The blood-stream would become tainted, and the brain, which requires pure blood, would suffer. ”

“ We have seen how it is always changing, always taking in food, always giving off waste materials. We have seen, too, that it grows and that it does work, and that in a large mass the cells which compose it share the labour instead of each component cell performing all the vital functions. We have now to consider the work which protoplasm does—in a word, the mechanical effect of the chemical actions just described.
The simplest movement of protoplasm is to be seen by the aid of the microscope in certain vegetable cells, where granules seem always streaming about in different directions. ”

“ Then he must make the action which his brain has decided is the most effective for his build the property of his spinal cord, that in a race he may use his strength economically, with his thoughts free to deal with the tactics of his opponents and the peculiarities of the course, or he will not make his supreme effort at the most advantageous moment. This is only one instance. Many men having a normal body develop organs of perception, not motion: the musician and the wine-taster, as well as the juggler and the athlete, are products of physical culture. ”