A treatise on the blood, inflammation, and gun-shot wounds / by John Hunter ; with notes by James F. Palmer.

  • John Hunter
Date:
1840
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on the blood, inflammation, and gun-shot wounds / by John Hunter ; with notes by James F. Palmer. 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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    and immediately began the artificial breathing. I then removed the sternum and cartilages, and opened the pericardium. While I conti- nued the artificial breathing, I observed that the blood in the pulmo- nary veins, coming from the lungs, the left auricle, the aorta, &c, was florid or dark just as I threw air into the lungs. I cut off a piece of the lungs, and found that the colour of the blood which came from the wound corresponded with the above effects. When I threw air into the lungs, so as to render the blood florid in the pulmonary veins, two kinds of blood issued from the wound; and when I left oft'blowing, the whole blood which passed out by the wound was of the dark colour. If the air is confined in the lungs of a quadruped, it soon loses its power over the blood, which remains dark, or has the appearance of becoming dark, be- cause dark-coloured blood is thrown in and it undergoes no change ; but if the same experiment is made on an amphibious animal it is a considerable time before the whole blood becomes dark, because in such animals the lungs are a reservoir of air, which of course con- tinues its influence over the blood for a longer time. This experiment I have repeated upon several animals, and com- monly for half an hour at a time, which was sufficient to allow me to make my observations with coolness and accuracy. In this part of the experiment it was curious to see the coronary arteries turn darker and darker, becoming like the veins which run on each side of them, and on blowing again resume gradually a brighter colour, till they became of a florid red. As respiration was generally pre- vented in the first part of the experiment, the blood was found at first wholly of a dark colour, and the heart large and hardly acting; but on throwing into the lungs fresh air, the heart began to act, upon which both auricles and ventricles became gradually smaller; then by stopping the respiration they again became larger and larger. The diminution of the heart's motion upon stopping respiration does not depend upon the immediate impression of improper blood on the left auricle and ventricle as a sedative, but upon the sympa- thetic connexion which exists between the heart and lungs (one action ceasing the other also ceases) ; which sympathy is esta- blished, because if the heart were to continue acting it would send improper blood into the body, by which it can be supported only a little while. The right auricle and ventricle also cease acting, although not so early, and for the same reason; because on the of recoveries from asphyxia has not been considerably reduced since the intro- duction of this means of resuscitation. To obviate this inconvenience, M. Leroy has recommended the adaptation of an arc of degrees to the handles of Hunter's bellows, graduated in such a manner as at once to show the proportions requisite for the different ages of life, to which are added moveable pipes to correspond, so as only to allow of the escape of the air in such quantities and in such periods of time as shall closely represent natural respiration. There can be no doubt that this is a very great improvement upon the old bellows, and ought universally to be adopted in all institutions for the recovery of drowned persons. (Magendie's Journ. de Phys., vii. viii. xi.)] 8