Lectures on the heart : delivered at the Melbourne University, Victoria, during the session of 1864 / by George B. Halford.

  • Halford, George Britton, 1824-1910.
Date:
1864
Catalogue details

Licence: Public Domain Mark

Credit: Lectures on the heart : delivered at the Melbourne University, Victoria, during the session of 1864 / by George B. Halford. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    M. Groux in the act of opening and closing this fissure at will. You will see in them, in addition, the expanded lung, the pulsating aorta, and contracting auricle and ventricle ; but this you must remember, that the sides are changed, that which is seen as the right side of the chest is the left, and vice versd. We will now examine the movements of the living machine which sets the wonderful currents of blood in motion. And first of the pericardium. You have most probably examined microscopically the ovum of the water-snail. You there see the embryo first a little dot, and then ultimately filling the egg, and during its imprisonment it may be seen moving and rolling, changing its form. From first to last the ovum contains the same amount of matter, and preserves its original form. So is it with the pericardium and its contents ; for although the chambers of the heart are ceaselessly filling and dis- charging, the aorta and pulmonary artery are as ceaselessly expanded and springing back; yet the amount of its contents must ever during health be the same. What the auricles lose the ventricles receive, what the ventricles lose the commencement of the large vessels admits, whilst, at the same time, the auricles are filling ; all these interchanges being facilitated by the small amount of fluid the peri- cardium contains : but in disease, where there is any obstruction to the cardiac movements, the quantity of fluid is usually found in- creased ; and this is also constantly the case in the reptile, the move- ments of whose heart is, when compared with that of man, laborious and irregular. I insist, then, upon the unvarying size of the pericardium, and the unsoundness of most of the conclusions which have been drawn from observations made on the hearts action after the removal of this sac. ’ In order to comprehend thoroughly the heart’s action, recourse must certainly be had to vivisection. Not one alone will suffice ; but I shall not have recourse to this proceeding on the present occa- sion, but refer you to diagrams for an outline of the chief phenomena. It is easy to perform these vivisections, but the necessary delicate observations cannot be made by a large number of spectators. No pain need be inflicted, for I have never but in one instance operated without the use of chloroform ; and when the animal has been under its influence I have removed the chest walls, keeping up artificial respiration with a pair of bellows, dropping occasionally into the valve-opening some of the anaesthetic. In this manner I last winter demonstrated to my class the heart’s act on, which was forcibly and rhythmically maintained beyond an hour, the animal never being permitted to recover consciousness. The instance in which I did not use chloroform was in the case of a turtle. I had previously made myself acquainted with the anatomy of the reptile, and was enabled to remove the whole plastron without scarcely losing any blood ; but I shall never repeat it, it is the “ damned spot ” on my Physiological fingers, and will not out. Moreover, there is a horror connected witk the proceeding I had never anticipated ; it is this,
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