On the early stages of inflammation / By Joseph Lister.

  • Joseph Lister
Date:
[1858]
Catalogue details

Licence: Public Domain Mark

Credit: On the early stages of inflammation / By Joseph Lister. Source: Wellcome Collection.

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    that the vessels are abnormally loaded with blood, and if the irritation be continued, the cuticle will be raised in the form of a blister. If, now, the loosened epidermis be artifi¬ cially removed on the earliest occurrence of effusion, a scarlet raw surface will be exposed; and on pressing the tender dermis firmly with the finger, and suddenly removing the pressure, it will be found that while the redness will for the most part have moment¬ arily disappeared, there will be many minute red points from which the blood cannot be expelled. This shows that, while the blood is in part still free to move, there are some minute vessels completely clogged with it. Again, if a portion of mustard be placed on the skin covering the dorsal aspect of one of the fingers, abnormal red¬ ness will very speedily be produced, which in the first instance disappears completely on pressure; but, if the mustard has been kept on long enough, can be only imperfectly dispelled; and if the application be still longer continued, vesication will be the result. I had lately the opportunity of examining the brain of a man who had died of tetanus, complicated with incipient meningitis; the post mortem appearance of the latter being maculiform congestion of the pia mater. Having stripped off a portion of the affected membrane, and carefully washed away with a camel’ s-hair brush the cerebral substance adhering to it, I applied the microscope to one of the affected spots, and found that all the minute vessels were filled with crimson blood, while those of the surrounding parts were comparatively pale. It was evident that the red corpuscles were, in the former, so closely crammed together as to produce the appearance of a uniform mass, while in the latter they were present only in their usual proportion to the liquor sanguinis. Thus it appears that in the human subject, inflammation, whether induced by mechanical irritation or by an acrid application such as mustard, or of spontaneous origin, is characterized at an early period by a certain amount of obstruction to the progress of the blood through the minute vessels; a phenomenon, which it is therefore of great importance to understand. It fortunately happens, that we have, in the transparent web of the frog’s foot, an opportunity of observing with the utmost facility the circulation of the blood in the living animal, and of watching the effects produced upon it by irritating causes. It may naturally appear very doubtful whether observations made upon creatures so low in the animal kingdom as the Amphibia, can with propriety be brought to bear upon human pathology. A few facts will, however, suffice to show that no such doubts need be enter¬ tained. If a portion of moistened mustard be placed upon the web of a frog, tied out under the microscope, the blood-vessels will soon be found abnormally red; and if the application be continued long enough, all the capillaries will become choked with cor¬ puscles so closely packed as to present the appearance of a uniform crimson mass; and by and by the epidermis will be found raised in the form of a blister over the part on which the mustard lay. These effects are precisely similar to those which we have seen to be produced by it upon the human skin; and before effusion has taken place, the vessels of the affected part exactly resemble those of the congested spot of inflamed pia mater above described. Again, if dry heat be made to act upon a part of the frog’s foot,