We do not pretend to know all this, nor are we "as certain of it as that two and two make four." Such certainty, though desirable, is not to be had in complex physiological questions. But we set down these propositions as being, so far as we can make out, in the present state of science, the verdict of physiology in the matter. Future inquiry may reverse that verdict; but as the physiologic evidence now stands, there is a quite appreciable preponderance in favor of the practice of smoking. Such was our own conclusion long before we had ever known, or cared to know, the taste of a cigar or pipe; and such it remains after eight years' experience in smoking. We shall endeavor concisely to present the rationale of the matter, dealing with some general doctrines likely to assist us both now and later, when we come to speak of alcohol.
We do not suppose it necessary to overhaul and quote all that the illustrious Pereira, in his "Materia Medica,"[3] and Messrs. Johnston and Lewes, in their deservedly popular books, have said about the physiologic action of tobacco. Their works may easily be consulted by any one who is interested in the subject; and their verdict is in the main confined to the general proposition that, from the temperate use of tobacco in smoking, no deleterious results have ever been proved to follow. More modern and far more elaborate data for forming an opinion are to be found in the great treatise of Dr. Anstie, on "Stimulants and Narcotics," which we shall make the basis of the following argument.[4]
In the first place, we want some precise definition of the quite vaguely understood word, "narcotic." What is a narcotic? A narcotic is any poison which, when taken in sufficient quantities into the system, produces death by paralysis. The tyro in physiology knows that death must start either from the lungs, the heart, or the nervous system. Now a narcotic is anything which, in due quantity, kills by killing the nervous system. When death is caused by too great a proportion of carbonic acid in the air, it begins at the lungs; but when it is caused by a dose of prussic acid, it begins at the medulla oblongata, the death of which causes the heart and lungs to stop acting. Prussic acid is, therefore, a narcotic; and so are strychnine, belladonna, aconite, nicotine, sulphuric ether, chloroform, alcohol, opium, thorn-apple, betel, hop, lettuce, tea, coffee, coca, hemp, chocolate, and many other substances. All these, taken in requisite doses, will kill by paralysis; and all of them, taken in lesser but considerable doses, will induce a state of the nerves known as narcosis, which is nothing more nor less than incipient paralysis. Every man who smokes tobacco, or drinks tea or coffee, until his hands are tremulous and his stomach-nerves slightly depressed, has just started on the road to paralysis: he may never travel farther on it, but he has at least turned the corner. Every man who drinks ale, wine, or spirit until his face is flushed and his forehead moist, has slightly paralyzed himself. Alcoholic drunkenness is paralysis. The mental and emotional excitement, falsely called exaltation, is due, not to stimulation, but to paralysis of the cerebrum. The unsteady gait and groping motion of the hands are due to paralysis of the cerebellum. The feverish pulse and irregular respiration are due to paralysis of the medulla oblongata. The flushed face and tremulous, distressed stomach, are due to paralysis of the sympathetic ganglia. And when a person is "dead-drunk," his inability to perform the ordinary reflex acts of locomotion and grasping is due in part to paralysis of the spinal centres. The coma, or so-called sleep of drunkenness, is perfectly distinct from true reparative sleep, being the result of serious paralysis of the cerebrum, and closely allied to delirium.[5] Now, what we have stated in detail concerning alcohol is also true of tobacco. A fatal dose of nicotine kills, just like prussic acid, by paralyzing the medulla, and thus stopping the heart's beating. The ordinary narcotic dose does not produce such notable effects as the dose of alcohol, because it is hardly possible to take enough of it. Excessive smoking does not make a man maudlin, but it causes restless wakefulness, which is a symptom of cerebral paralysis, and is liable, in rare cases, to end in coma. Its action on the cerebellum and spinal cord cannot be readily stated; but its effect on the medulla and sympathetic is most notable, being seen in depression or feeble acceleration of the pulse, trembling, nausea of the stomach, and torpidity of the liver and intestines. Nearly or quite all of these effects producible by tobacco, are producible also, in even a heightened degree, by narcotic doses of tea and coffee. A concentrated dose of tea will produce a paralytic shock; and a single cup of very strong coffee is sometimes enough to cause alarming disorder in the heart's action. All these narcotic effects, we repeat, are instances of paralytic depression. In no case are they instances of stimulus followed by reaction; but whenever a narcotic dose is taken, the depressive paralytic action begins as soon as the dose is absorbed by the blood-vessels. The cheerful and maudlin drunkard is not under the action of stimulus. His rapid, irregular, excited mental action is no more entitled to be called "exaltation" than is the delirium of typhoid fever. In the one case and in the other, we have not stimulation but depression of the vitality of the cerebrum; in both cases, the nutrition is seriously impaired; in both cases, molecular disorganization of the nerve-material is predominant.
So much concerning narcotics has been established, with vast and profound learning, by Dr. Anstie. No doubt, by this time, the reader is beginning to rub his eyes and ask, Is this the way in which you are going to show that smoking is beneficial? You define tobacco as a poison which causes paralysis, and then assure us that it pays to smoke! It is true, this has at first sight a paradoxical look; but as the reader proceeds further, he will see that we are not indulging either in paradoxes or in sophisms. We wish him to take nothing for granted, but merely to follow attentively our exposition of the case. We have indeed called tobacco a poison,—and so it is, if taken in narcotic doses. We have accused it of producing paralysis,—and so it does, when taken in adequate narcotic doses. We would now call attention to a property of narcotics, which is well enough known to all physiologists, but is usually quite misapprehended or ignored by popular writers on alcohol and tobacco.[6] We allude to the fact that narcotics, when taken in certain small quantities, do not behave as narcotics, but as stimulants; and that they will in such cases produce the exact reverse of a narcotic effect. Instead of lowering nutrition, they will raise it; instead of paralyzing, they will invigorate. Taken in a stimulant dose, tobacco is not only not a producer, it is an averter, of paralysis. It is not only not a poison, but it is a healthful, reparatory stimulus.
It is desirable that this point should be thoroughly understood before we advance a step farther. Here is the pons asinorum in the study of narcotics, but it must be crossed if we would get at the truth concerning alcohol and tobacco. Alcohol is a poison, says the teetotaler, who means well, but has not studied the human organism; alcohol is a poison, and once a poison always a poison. Nothing can seem more logical or reasonable, so long as one knows nothing about the subject. A quart of brandy is admitted to be poison; is not, therefore, a spoonful of brandy also poison? We reply, by no means. Physiological questions are not to be settled by formal logic. Here the quantity is the all-essential element to be taken into the account. Common salt, in large doses, is a virulent poison; in lesser doses it is a powerful emetic; in small doses it is a gentle stimulant, and an article of food absolutely essential to the maintenance of life. In the spirit of the teetotaler's logic, then, it may be asked, If a pound of salt is a poison, is not a grain of salt also a poison? We reply, call it what you please, you cannot support life without it. So from the poisonous character of the quart of brandy, the poisonous character of the spoonful is by no means a legitimate inference. The evil effects of the small dose are to be ascertained by experiment, not to be taken for granted. Logic is useful in the hands of those who understand the subject they reason about; but in other hands it sometimes leads to queer results. It was logic that used up the one-hoss shay.
The general principle to guide us here is that of Claude Bernard, that whatever substance or action, in due amount, tends to improve nutrition, may, in excessive amount, tend to damage nutrition. In the vast majority of cases the difference between food and poison, between beneficent and malignant action, is only a difference of quantity. Oxygen is the all-important stimulus, without which nutrition could not be carried on for a moment. It constitutes about one-fifth of our atmospheric air. Let us now step into an atmosphere of pure oxygen, and we shall speedily rue such a radical proceeding. We shall live so fast that waste will soon get ahead of repair, and our strength will be utterly exhausted. The effect of sunlight on the optic nerve is to stimulate the medulla, and increase thereby the vigor of the circulation. But too intense a glare produces blindness and dizziness. The carpenter's thumb, by friction against the tools he uses, becomes over-nourished and tough; but if the friction be too continuous, there is lowered nutrition and inflammation. Moderate exercise enlarges the muscles; exercise carried beyond the point of fatigue wastes them. The stale prize-fighter and the overworked farmer are, from a physical point of view, pitiable specimens of manhood. A due amount of rich food strengthens the system and renders it superior to disease; an excessive amount of rich food weakens the system, and opens the door for all manner of aches and ailments. A pinch of mustard, eaten with meat, stimulates the lining of the stomach, and probably aids digestion; but a mustard poultice lowers the vitality of any part to which it is applied. Moderate emotional excitement is a healthful stimulus, both to mind and body; but intense and prolonged excitement is liable to produce delirium, mania, or paralysis. Ne quid nimis, therefore, the maxim of the wise epicurean, is also the golden rule of hygiene. If you would keep a sound mind in a sound body, do not rush to extremes. Steer cautiously between Scylla and Charybdis, and do not get wrecked upon the one or swallowed up in the other.
Few persons who have not been specially educated in science have ever learned this great lesson of Materia Medica, "that everything depends on the size of the dose." It is not merely that a small dose will often produce effects differing in degree from those produced by a large dose; nor is it merely that the small dose will often produce an effect differing in kind from that of the large dose; but it is that the small dose will often produce effects diametrically opposite and antagonistic to those of the large dose. The small dose may even serve as a partial antidote to the large dose. The adage concerning the hair of the dog that has bitten us, embodies the empirical wisdom of our ancestors on this subject. Especially is this true of all the substances classed as narcotics. In doses of a certain size, they, one and all, produce effects exactly the reverse of narcotic. If anything is entitled to be called a deadly narcotic poison, it is strychnia, which, by paralyzing the spinal cord, induces tetanic convulsions: yet minute doses of strychnia have been used with signal success in the cure of hemiplegic paralysis. In teething children, the pressure upon the dental branches of the trigeminal nerve sometimes causes an irritation so great as partly to paralyze the medulla, inducing clonic convulsions, and perhaps death by interference with the heart's action.[7] In these cases, alcohol has been frequently used with notable efficacy, averting as it does the paralysis of the medulla. Epileptic fits, choreic convulsions, and muscular spasms—such as colic, and spasmodic asthma—are also often relieved by the tonic or anti-paralytic action of alcohol. And how often has the temperate smoker, after some occasion of distressing excitement, his limbs and viscera trembling, his nerves "all unstrung," or incipiently paralyzed,—how often has the temperate smoker found his whole system soothed and quieted, and the steadiness of his nerves restored, by a single pipe of tobacco! That this is due to its action as a counteracter of paralysis is shown by the fact that tobacco has been successfully used in tetanus,[8] in spasm of rima glottidis,[9] in spasmodic asthma,[10] and in epilepsy.[11] For these phenomena physiology has but one explanation. They are due to the fact that narcotics, in small doses, either nourish, or facilitate the normal nutrition of the nervous system. They restore its equilibrium, enabling it, with diminished effort, to discharge its natural functions. And anything which performs this office is, in modern physiology, called a stimulant.
Here then we have obtained an important amendment of our notion of a narcotic. A narcotic is a substance which, taken in the requisite dose, causes paralysis. But we have seen that by diminishing the dose we at last reach a point where the narcotic entirely ceases to act as a narcotic and becomes a stimulant. What then is a stimulant? There is a prejudice afloat which interferes with the proper apprehension of this word. People call alcohol, indiscriminately, a stimulant; and when a man gets drunk, he is incorrectly said to be stimulating himself; stimulants are therefore looked at askance, as things which demoralize. The reader is already in a position to know better than this. He sees already that it is not stimulus but narcosis which is ruining the drunkard. Nevertheless, that he may understand thoroughly what a stimulant is, we must give further explanation and illustration.
Food and stimulus are the two great, equally essential factors or co-efficients in the process of nutrition. We mean by this, that in order to nourish your system and make good its daily waste, you need both food and stimulus. You must have both, or you cannot support life. Day by day, in every act of life, be it in the acts of working and thinking which go on consciously, or be it in the acts of digestion and respiration which go on unconsciously, in the mere keeping ourselves alive, we are continually using up and rendering worthless the materials of which our bodies are composed. We use up tissue as an engine uses up fuel; and we therefore need constant coaling. Tissue once used is no better than ashes; it must be excreted, and food must be taken to form new tissue. Now the wonderful process by which digested food is taken up from the blood by the tissues—each tissue taking just what will serve it and no more, muscle-making stuff to muscle, bone-making stuff to bone, nerve-making stuff to nerve—is called assimilation, nutrition, or repair. It is according as waste or repair predominates that we are feeble or strong, useless or efficient. When repair is greatly in excess, as it usually is in childhood and youth, we grow. When waste is greatly in excess, we die of consumption, gangrene, or starvation. When the daily repair slightly outweighs the daily waste, we are healthy and vigorous. When the daily repair is not quite enough to replace the daily waste, we are feeble, easily wearied, and liable to be assailed by some illness.
Now, in order to carry on this great process of nutrition, we have said that food and stimulus are equally indispensable. We must have food or we can have nothing to assimilate; but we must also have stimulus, or no assimilation will take place. The unstimulated tissue will not assimilate food. The nutritive material rushes by it, unsought for and unappropriated, and no repair takes place. There are some people whom no amount of eating will build up: what they need is not more food, but more nerve stimulus; they doubtless eat already more than their tissues are able to assimilate. In pulmonary consumption, the chief monster which we have to fight against is impaired nutrition, the tubercles being only a secondary and derivative symptom.[12] The problem before us, in dealing with consumption, is to improve nutrition, to make the tissues assimilate food. And to this end we prescribe, for example, whisky and milk—a food which easily reaches the tissues, and a stimulant which urges them to take up the food sent to them. We define, therefore, a stimulant as any substance which, brought to bear in proper quantities upon the nervous system, facilitates nutrition.