In present conditions, and so far as we are able to see at present, liquefied gases are for a long time not likely to serve any greater mechanical purpose than that of furnishing a highly portable apparatus by which great power can be developed for a short time at any required place. It is easy to believe that it could not be otherwise employed with any economy, even when discovery has greatly simplified the now difficult process of liquefaction. But in regard to this matter, and to almost every other mechanical and engineering improvement suggested in the present work, it is of the first importance to remember that the conditions in which the work of the world a hundred years hence will be done are certain to differ very greatly from anything we know to-day; and that procedures at present not merely out of proportion, but in themselves actually chimerical, will become perfectly workable in the new circumstances of another century. No doubt the problems at present involved make many of the developments herein suggested almost laughable to those who examine the subject without imagination. But what could have been thought of a man who, when Oersted discovered the influence of a battery current on the compass needle, suggested that the discovery might, in much less than a hundred years, be practically developed in such unforeseen ways as to produce locomotive machines capable of carrying vast weight at a speed of perhaps a hundred miles an hour? He would have been told that such predictions “could only have originated from an imperfect comprehension of the problems involved.” But we know that they would have been perfectly sound, though it would have been difficult to withhold assent from the derision which instructed hearers would have poured upon them. The effect of any scientific discovery can only be measured when we are in a position to judge of the conditions in which it may be applied, and the further discoveries which may affect it—a consideration which will help us against the danger of undue caution in estimating the possible developments of recent discovery when utilised in the conditions of the next century and reinforced by inventions and discoveries yet to come.
A like caution will, however, teach us to restrain our expectations from the new knowledge which radium appears to be gradually unfolding, not because there is any doubt that radio-activity will ultimately bring priceless gifts to civilisation, but because in our present ignorance of all but a few facts concerning it we can form no possible conjecture as to the lines these gifts will follow. Already we seem to have seen in some of the radium experiments one “element” turn into another. If this should develop until we acquire the power which used to be dreamed of as transmutation, the social and economic upheavals which would result beggar imagination.[4]
The photographic effect of Röntgen rays has already[5] been the subject of a suggestion, and even the facts now remotest from practical use in connection with the rays of various sorts so much discussed in the scientific newspapers will no doubt be utilised in a manner or in manners far removed from the limited employment in therapeutics already found for them.
And indeed medicine, not the most progressive of modern sciences, will no doubt make vast strides during the period under discussion.
It would be altogether fallacious to forecast the position and probable achievements of medical science in a century’s time on the line of simple development from the practice of to-day. The changes will be revolutionary rather than evolutionary. When it is remembered that only fifty years ago limbs were hacked from the quivering flesh of the sentient patient, held down by muscular assistants lest the violent struggles of his agony should embarrass the surgeon, and that wounds of all sorts festered and decayed until a hospital reeked with their impurity—in other words, that discoveries so great as anæsthesia and antisepsis are well within living memory—we need not hesitate to predict for the present century changes in medical and surgical science almost inconceivable by the light of our present attainment. Anæsthetics—of which the local kinds, as cocaine and eucaine, are of entirely recent use—represent an advance in one direction. Antiseptic surgery, which is the prevention and correction of blood and wound-poisoning by chemical disinfectants, represented an advance of a different kind. But antisepsis is already on the point of being superseded by the far more rational and scientific method of asepsis, or the exclusion from open wounds of all the germs which can set up inflammation and festering. The change is typical.
The direction in which medicine is chiefly working at the present time is that of introducing into the body one disease with the idea of excluding other diseases. It is conceived that cow-pox is antagonistic to small-pox, erysipelas possibly to cancer, and so on. All the talk in medical circles is of serum and attenuated virus. And, apart from animal products administered by injection, we cure or attempt to cure all diseases by administering poisons—animal, vegetable or mineral. Just as by antiseptics we poison the germ which causes festering and inflammation, so by drugs we attempt to poison disease—for all drugs are practically poisons. The principle of their administration is almost wholly empirical. If you ask a doctor why phenacetin reduces fever, it is impossible to get beyond a metaphysical explanation. He will reply that phenacetin reduces fever by lowering the blood pressure, or something of that kind. But this merely re-states the problem. Why does phenacetin lower blood pressure? We do not know. The substitution of asepsis for antisepsis—that is, of cleanliness for disinfection—has hardly yet been perceived to be in a certain sense the greatest advance in therapeutics since Hippocrates. It probably contains the germ of future medical treatment. Hereafter we shall not try to cast out devils of disease by other disease-germs only less devilish. We shall learn enough of the causes of disease to stop them at their source, and knowledge growing from more to more, which has taught us exactly how “matter in the wrong place”—of whatever sort—is the source of all disease, will also show how matter may generally be kept in its right place.
Although comparatively little progress has been made by the curative use of rays, other discoveries, of which we have even now passed the brink, will have an enormous effect on medicine and surgery. Already certain kinds of light cure rodent ulcer, one of the most hideous and terrible diseases, not by the importation of fresh substances into the body but by the modification of the tissues themselves. When radiation has been fully studied it will almost certainly be found that the sun, which is the source of practically all terrestrial activity, has been showering upon us, ever since the homogeneous vapour which was the birth-stuff of the universe aggregated itself into worlds and suns and planets, rays which are capable of correcting every sort of disease-germination and, properly used, of preventing it. The absolute deadliness of unmodified sunlight to many sorts of disease-germs is recognised already. The value of sun-baths—the exposure of the whole body, undraped or only lightly covered, to the sunlight—is already discussed in connection with anæmia, chlorosis and the early stages of consumption. When we know just where all disease originates, and why it develops, it seems likely that sunlight and oxygen its child will prevent nearly all disease and cure whatever disease accidentally arises. In place of temporary and dangerous expedients like antiseptics, serum and corrective poisons, we shall import nothing into the human organism, but only exclude what ought to be kept out, and modify into innocuousness what has found its way in.
A great part of the disease we call constitutional, as distinguished from infective, arises from food, either because the food itself is not free from disease, or because, from excess in quantity or error in choice, the food we take sets up the production of poisons in the course of digestion, and by yielding, for instance, lactic or uric acid to the blood causes rheumatism or gout, or by introducing into the stomach matter in a state of incipient decay, favours typhoid and other fevers.
When, for reasons already indicated, animal food has been eliminated from the menu one great source of disease will have been got rid of.
When we completely understand the nature of the infective and contagious diseases it seems well within the bounds of possibility that the systematic destruction of their germs may be carried far enough to remove them altogether from the planet.[6] We have now, even by the highly imperfect measure of quarantine and a period of muzzling (from which, on no evident ground except that it would interfere with the amusements of the governing class to include them, sporting dogs were excluded), apparently banished hydrophobia from Great Britain. If it prove to be the case that just as hydrophobia cannot arise spontaneously, but requires to be “started” by the entry into the blood of an animal of an existing infection, other infective diseases require pre-existing disease before they can arise, we may get rid of them altogether. The dream may appear a wild one. But it is not wilder than the dreams of a thinker who anticipated any one of a hundred common facts of to-day must have appeared to our great-great-grandfathers.