On the restoration of health : being essays on the principles upon which the treatment of many diseases is to be conducted / by Thomas Inman.

Date:: 1870

Credit: On the restoration of health : being essays on the principles upon which the treatment of many diseases is to be conducted / by Thomas Inman. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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$the disease known as liydrophobia, we are bound to acknowledge that the effect of something introduced into the system may be recognised long after its entrance. Syphilis is a notable example of this, for the infection may be introduced by a parent and run through succeeding generations. Not only are animal poisons thus potent in small quantities, but certain mineral poisons are of equal power. Mercury will, in some few cases, act quite as severely as syphilis in others, and quinine has been known to produce permanent deafness. Yet, as a rule, every substance which is used in medicine pro- duces its definite effect in a very short period of time, after which it ceases to have influence. For example, a dose of opium if it operates to-day will not operate to-morrow, nor will a blister applied to-morrow postpone its effects for a twelve- month. If we could always generalise thus, we might be able to promote the art of medicine to the position of a true science ; we are, however, unable to do so, because we find that a drug will do miscliief long after its introduction into the system and its succeeding expulsion: for example, a dose of calomel may sometimes, though very rarely, bring about caries of the bones of the loAver jaw, long after the drug has been eliminated, and lead will produce wrist di'op, although we are unable to demon- strate its actual XDresence in the muscles of the fore arm. Still farther, we can point to cases in which a single dose of quinine, opium, or other drug, has so completely altered the state of the constitution produced by marsh malaria, that ague and tic- doloureux have been suspended indefinitely. Granting, then, that animal and vegetable substances can ox^erate in very small quantities, and through very considerable periods of time, we nevertheless aver that, as a general rule, chemical potencies operate on the human body in direct propor- tion to the quantity introduced, and that the effect depends upon the manner in which their inorganic force modifies the vital force already existent. The absolute extent to which the vital phe- nomena can be influenced by chemical or foreign agenc}- are only ascertained by trial, inasmuch as it varies in individuals. As a general rule, and one applicable to ninety-nine cases out of a hundred, we may say that medicines act much in the same time, and their effects endure as long as that of a good breakfast, dinner, or supper. If the dose be large, the effect is commensurate, whether it be of bhang, or beef, or beer, cr brimstone : we no more expect to find the influence of a dose of medicine which has been taken on New Year's day, at the feast of St. Valentine, than we should expect to find a person drunk on ]\Iay-day from a bottle of champagne swallowed on the twenty-liftii of ]\Iarch. In like manner, we conclude that the effects of a medicinal agent are in proportion to its quantity.$