Lectures on the principles and practice of physic : delivered at King's College, London / by Thomas Watson.

  • Watson, Thomas, Sir, 1792-1882.
Date:
1844
Catalogue details

Licence: Public Domain Mark

Credit: Lectures on the principles and practice of physic : delivered at King's College, London / by Thomas Watson. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    actual disease itself—the actual condition of that part, or those parts of the body, from which the whole train of morbid phenomena essentially (lows. When we know those parts, and that condition, we name the disease accordingly. When we do not, we call the complaint after the group of symptoms by which it is characterized' The term proxi- mate cause is therefore an unnecessary term:—it is moreover, to learners, a puzzling term, and tends to give to the consideration of disease a scholastic and repulsive aspect. I wish you to get into the habit of contemplating the whole science of medicine under its simplest and plainest form. I am sure we may very well abolish the term proximate cause alto- gether and having now given an explanation of its meaning, for your guidance when you meet with it in books, I shall never employ it, in these lectures, except perhaps in a quotation, again. In strictness of language, one event is held to be the cause of another event which fol- lows it, when the first being absent, the second never occurs—and the first bring preeent, the second never fails to occur, unless some other event intervene to prevent it. But the causes of disease will not bear to be spoken of after so strict a fashion. We perceive that ceitain external circumstances {qxix nos circumstant) often precede such and such dis- eases; and that the diseases seldom happen when these circumstances are not previously observable; and we begin to regard those circumstances as exciting causes of those dis- eases. We find that the diseases are much more frequent among persons known to have been exposed to the agency of the presumed causes, than among persons who are not known to have been so exposed. The evidence at first is presumptive only. But the more uniform their conjunction, and the more rare their disjunction, the more confidently do we ascribe to the two consecutive events the. relation of cause and effect. By this kind of observation a number of exciting causes of disease have been clearly established to be such. But recollect, certain circumstances being present, such arid such diseases do often, not always, follow. Some persons are more liable to be affected by the operation of many of these ascertained causes than others arc; and the same persons more liable to be influenced by the same cause at one time than at another. And special circumstances, existing in par- ticular cases, will be found to account for this variable operation of known exciting causes upon the bodily health. These special circumstances may properly be called predisposing causes. Thus, of a score of persons exposed to the same noxious influence—to the com- bined influence of wet and cold during a shipwreck for example—one shall have catarrh, another rheumatism, a third pleurisy, a fourth ophthalmia, a fifth inflammation of the bowels, and fifteen shall escape without any illness at, all. A man shall do that with im- punity today, which shall put his life in jeopardy when he repeats it next week. It is not therefore the exciting cause alone that in all cases determines the disease. Something —nay much—or all—will frequently depend upon the condition of the body at the time when the exciting cause is applied:—and this condition of the body, which we call pre- disposition, will depend upon circumstances then or previously in operation—and these circumstances are, in our language, predisposing causes. Do not confound, as many seem to do, the predisposition with the circumstances creating it. The predisposition is a certain state of the body—the predisposing cause is what pro- duces that state. The cause of the predisposition is the predisposing cause of the disease. A predisposing cause may therefore be defined to be any thing whatever which has had such a previous influence on the body as to have put it in a condition of greater suscepti- bility to the exciting cause of the particular disease. It is sometimes difficult, or impossible, to say of a given cause whether it ought to be ranked among the exciting or the predisposing causes: whether it has prepared the system for being affected by some other agent, or whether it has itself produced the disease- but for the most part the distinction is real—and sufficiently well marked—and of great im- portance to be attended to. Disease may sometimes be averted, even in despite of strong and fixed predisposition to it, if we know and can guard against the agencies by which it is capable of being excited. A man may inherit a proclivity to consumption, yet fortunately escape that fatal complaint by timely removal to a warm and equable climate, and by other suitable precautions; that is, by avoiding whatever tends to rouse the dormant tendency into action. On theother