Volume 1

The works of John Hunter ... with notes / Edited by James F. Palmer. [With life and bibliography of Hunter by D. Ottley].

  • Hunter, John, 1728-1793
Date:
1835-1837
Catalogue details

Licence: Public Domain Mark

Credit: The works of John Hunter ... with notes / Edited by James F. Palmer. [With life and bibliography of Hunter by D. Ottley]. Source: Wellcome Collection.

    243/684 (page 209)
    effect could not be prevented, or afterwards either removed, diminished, or increased with advantage, it will be proper to change it to some other more in our power to remove, as,- for instance, by converting the vene- real into common inflammation. If the disease is already formed, we ought to know the modes of action in the body and in parts, in their endeavour to relieve themselves; the powers they have of restoring themselves, and the means of assisting those powers. Or, if these prove insufficient, we judge, by all the attending circumstances, how far excision may be necessary, and what condition of the constitu- unknown and invisible,) being denominated the cause, the resulting phenomena the effect, and the conditions under which that effect is produced, the/aio. Thus, all bodies fall to the earth, and all bodies also suffer an expansion of their particles by the appli- cation of heat. Here the principles of gravitation and heat are the causes, the descent and expansion of the bodies the effects, and the rates according to which these effects take place, the laws of gravitation and heat. Causation is attributed merely in conse- quence of the invariablencss of the phenomena, and not in consequence of any know- ledge which we possess of the intimate relation of causes and effects. It is not in general difficult to deduce the laws of physical agents, in consequence of the power which we possess of simplifying and varying the conditions of our experi- ments, so as in the first instance to separate all extraneous influences or disturbing causes, and in the second place to verify the results thus obtained by every possible combination of opposing circumstances. Such certainty, however, is rarely attainable in regard to organized bodies, in consequence of the reaction of the parts of which they consist upon one another, and the consequent impossibility of observing the effects of organic agencies in their simple state. The conditions under which any given class of phenomena are observed are continually varying, and a variety of extraneous causes are mixed up in almost every case, so that, from the most careful experiments, it is still extremely possible to mistake the conclusion, and to deduce laws which are expressive only of a part of the facts. These circumstances afford no just ground for under- valuing physiological principles,.although they are calculated to inspire a wary caution in arguing with too much positiveness from principles of this kind. We would say, “ Est quodam prodire tenus si non datur ultra.” It is scarcely necessary to observe that causes differ greatly among themselves. It would be absurd to confound the principle of heat, the expansion of steam, and the ma- chinery by which the power thus generated acts, as causes of the same kind. The remote and the proximate cause in such a case have no immediate relation, but are connected together by a number of intermediate circumstances which, like the steps of an argu- ment, unite the conclusion to the premises. It is very necessary to bear this in mind in physiological reasoning, in consequence of our almost total ignorance of these inter- mediate links in the chain of causation. In the instances above adduced by the author, we have no knowledge of the mode in which the poison of a rabid animal, or the poison of syphilis, produce their effects on the animal body ; nor how mercury and other medi- cines should tend to eradicate the latter from the constitution. We arc unable in these cases to advance a step further than to perceive the necessity of absorption of the poison, after which all is conjecture. A full perception of the whole sequence of effects would doubtless at once discover the precise nature of the remedy, as well as the proper cases m which it should be administered. nhnl,rv«'=‘de in consequence of the indefinite and not very final and m ‘^e word cttasc. The final and efficient causes are frequently confounded.] VOL. I. p