Observations and experiments on the efficacy and modus operandi of cupping-glasses, in preventing and arresting the effects of poisoned wounds / by Caspar Wistar Pennock.

Date:
1828
Catalogue details

Licence: Public Domain Mark

Credit: Observations and experiments on the efficacy and modus operandi of cupping-glasses, in preventing and arresting the effects of poisoned wounds / by Caspar Wistar Pennock. 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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    W e now proceed to offer some remarks on Dr. Barry’s theory of the modus operandi of the cupping-glasses, etc. Agreeably to Dr. Barry’s view, external absorption is not a vital function, but it, as well as the circulation in the absorbing vessels, is a physical effect caused by atmospheric pressure, the fluids pass- ing through the absorbents precisely as a liquid is forced into, and rises into a Torricellian vacuum. Dr. Barry, in support of his opinions, appeals to the series of ex- periments: the truth of the results of which, as stated by him, I have had the pleasure to confirm. His view, however, of the modus ope- randi of the cupping-glasses in preventing the effects of external poi- sons are, I am induced to believe, entirely erroneous. The results of some experiments which I instituted with a view of testing the principle, whether their efficacy depends merely on the ab- straction of atmospheric pressure, have convinced me that such is not the fact. It is true that the exhaustion of air from within the bounds of the glass, relieves that portion of the body inclosed within its periphery from the usual atmospheric pressure: but the parts beneath the cir- cumference of the cup, suffer an increase of pressure proportionate to the diameter of the glass. Thus the glass which I used, being one inch and a quarter in diameter, the animal suffered an increase of pressure on the parts just indicated of at least fifteen pounds. Convinced of the truth of this position, and supposing that increased pressure, rather than a diminution of it, was the cause of the arrest of the poisonous action, I instituted the following experiments:— Experiment A.—I inserted one grain of strychnine into the cellu- lar tissue of the thigh of a small and feeble rabbit: the poison was in- troduced through a quill to some distance from the incision in the skin, and there deposited. Pressure equivalant to fifteen pounds was immediately made over the poisoned surface, by applying to it the leg of a chair loaded with the abovementioned weight. No symptoms of poisoning occurred during the first forty-five minutes, and sup- posing it possible that the strychnine had not its usual poisonous cha- racter, we determined to test it on another rabbit of about the same size and vigour. One grain of the poison having been inserted into the thigh of this animal, and he left to his fate, he died in five minutes. It was thus determined that the strychnine now used, was more viru- lent and energetic than any previously employed. No symptom of poisoning having been evinced by the first rabbit during fifty-two minutes after the application of the poison, the pres-