Tobacco is used as a sedative or narcotic over a larger area, and among a greater number of people than any similar substance, opium being the next to it in these respects, and the hemp-plant the third. Tobacco-leaves, when submitted to chemical analysis, yield nicotine (q.v.), which is its most characteristic constituent, albumen, a gluten like substance, gum, resin, malic and citric acids, and a large amount of inorganic con stituents, 100 parts of the dry leaf yielding from about 19 to 27 per cent of ash, in which potash, lime, and silica preponderate. In a physiological and medical point of view, the analysis of the smoke of tobacco is of far more importance than that of the leaf. From the researches of Dr. Richardson, it appears that although " the widest differences pre , vail in respect to the products arising from differing cigars, differing kinds of tobacco, and differing pipes," there are certain substances which are common to all varieties of tobacco-smoke. Firstly, there is in all tobacco-smoke a certain amount of watery vapor, impregnated with various substances, from which it may be separated. Secondly, a small quantity of free carbon is always present; it is to the, presence of this constituent that the blue color of the smoke is due. " It is this carbon," says Dr. Richardson, "which in confirmed and inveterate smokers settles on the back part of the throat and on the lining membrane of the bronchial tubes, creating often a copious secretion, which it discolors, and which is coughed up of a dark cooly appearance."—For and Against Tobacco, Lond. 1865, p. 5. Thirdly, there is a certain quantity of ammonia present. The presence of the ammonia gives to the smoke an alkaline reaction. Moreover, " it is the ammonia that bites the tongue after long smoking; it is the ammonia that makes the tongue and throat of the smoker so dry, and induces him to quaff as he smokes, and that partly excites the salivary glands to secrete so freely. The ammonia also exerts an influence on the blood."—Richardson, op. at., p. 6. Fourthly, carbonic acid is always present, as may be shown by its action on lime-water. The amount differs extremely in the smoke from different kinds of tobacco, but, according to Dr. Richardson, it may be fairly inferred that the sleepiness, headache, and lassitude which follow the prolonged. inhalation of tobacco-fumes, are largely due to this agent. Fifthly, tobacco-smoke yields a product having an oily appearance, and possessing poisonous properties. It is popularly known as oil of tobacco; and on further analysis, it is found to contain three substances —viz., a fluid alkaloid, nicotine; a volatile substance having an empyreumatic odor; and an extract of a dark resinous character, having a bitter taste. The symptoms of tremor, palpitation, and paralysis which ensue after excessive smoking, especially in persons unaccustomed to indulgence in this practice, seem to depend upon the nicotine, which is known, by experiment, to be highly poisonous. " The peculiar smell of stale tobacco smoke, which hangs so long on the breath of the smoker, and on articles of clothing, is derived from the volatile empyreumatic substance; and the exceedingly nauseous sharp taste which is recognized by every unpracticed smoker, when he takes a foul pipe into his mouth, is due to the bitter extract. It is apparently this extract which creates vom iting in persons unaccustomed to tobacco, and of which the body after a time becomes tolerant."—Richardson, op. cit., p. 8. Hence it appears that the more common effects are due to the carbonic acid and the ammonia; while the rarer and more severe are due to the nicotine, the empyreumatic substance, and the resin.
It is unnecessary to 'enter into details regarding the symptoms of slight tobacco poisoning, because they are well known to the great majority of the male population. Fortunately, the effects produced by tobacco' are very transitory, as the poison finds a ready exit from the body. The system, after being subjected for a few times to the poisons of tobacco-smoke, becomes accustomed to their influence, the distressing symptoms no longer occur, and a condition of "tolerance" is established. From the extensive investigations of Dr. Richardson, it appears that there are no grounds for believing that smoking can produce any organic changes. It may, however, produce various functional disturbances: (a) On the stomach. (b) On the heart, producing
debility and irregular action. (c) On the organs of the senses, as dilatation of the pupil, confusion of vision, subjective sounds, etc. (d) On the brain, suspending the waste of that organ, and oppressing it if it be duly nourished, but soothing it if it be exhausted. (e) On the nerves leading to over-secretion of the glands which they control. (f) On the mucous membrane of the mouth, causing what has been described as the " smoker's sore throat." " The disease consists of an irritable state of the mucous membrane at the back of the throat, redness there, dryness, a tendency to cough, and an enlarged soft, sore condition of the tonsils, rendering every act of swallowing painful and difficult." It may exist without detection for a long time; but if a damp, cold, foggy state of the air comes on, the throat becomes troublesome and painful, enlargement of the tonsils is detected, and the symptoms become much aggravated by any attempt to smoke. Thid, condition is more readily induced by the use of cigars than of pipes: it is quite incur able so long as the patient continues to smoke, but soon disappears when the use of tobacco is entirely suspended. In association with this condition of the throat, the gums are usually abnormally pale and firm. (g) On the bronchial surface of the lungs, sustaining any irritation that may be present, and increasing the cough. There is no evidence that tobacco-smoke can cause specific diseases, such as insanity, epilepsy, St. Vitus's dance, apoplexy, organic disease of the heart, cancer, consumption, or chronic bronchitis. If, as is universally allowed, tobacco possesses, like alcohol, arsenic (in minute doses), opium, tea, coffee, etc., the power of arresting the oxidation of the living tissues, and thus checking their disintegration, it follows (1) that the habit of smoking must be "most deleterious to the young, causing in them impairment of growth, pre mature manhood, and physical degradation" (Richardson, op. cit., p. 73); and (2) that the habit may be conducive to the physical well-being of the individual, provided lie cannot supply himself with sufficient nourishing food to supply the daily tear and wear of the muscular and nervous systems.
For a long controversy on the question, Is Smoking Injurious to Health? in which sir Ranald Martin, Mr. Solly, Dr. Ranking, and other medical men took a part, the reader is referred to the 1st volume of The _Lancet for 1857. The whole matter is very fairly summed up by Dr. Richardson in the excellent pamphlet from which we have so freely borrowed in this article—a memoir which we can cordially recommend to all who take an interest in this subject. Before the full maturity of the system is attained, even the smallest amount of smoking is hurtful; subsequently, the habit is, in most instances, only prejudicial when it is carried to excess. We cannot honestly say more against tobacco than can be urged against any other luxury, and of nearly every luxury it is the least injurious. "It is innocuous as compared with alcohol; it does infinitely less harm than opium; it is in no sense worse than tea; and by the side of high living altogether, it contrasts most favorably."—Richardson, op. cit., p. 75. In conclusion, a word or two may be said regarding the kind of pipe that should be used. A long, perfectly clean pipe, composed of an absorbing material like clay or meerschaum, which can suck up the oily matter before it reaches the mouth, is always to be preferred; and :NI. Melsens, to whom the scientific world is indebted for many ingenious applications of chemistry to hygiene and the treatment of diseases, has recently suggested, that if a plug of cotton, saturated with a strong solution of citric or tannic acid, were placed in the stem, so as to filter the smoke before it reached the mouth, all the nicotine would be seized by and combine with the acid. The different kinds of tobacco exert a different influence on the smoker according to the amount of noxious ingredients which they contain. Tbus, cavendish, pigtail, and coarse shag yield the oily matters in much more abundance than Latakia or Turkish, which are hence termed mild tobaccos. Cigars produce dyspepsia much more rapidly than pipes, for in smoking them, unless with a long mouth-piece, nicotine is necessarily absorbed.