368 Dr. Richardson on the possibility of [June 15, 



Advantages and dangers of galvanism. la considering the advantages 

 that may be derived from galvanism, certain dangers of it must not be for- 

 gotten. My experiments clearly showed that the natural muscular irrita- 

 bility, while it is for a short time made more active by galvanism, is shortened 

 in duration. This is natural. The irritability of muscle is in proportion 

 to the degree of force which remains in it after the blood is withdrawn, 

 which force is evolved in proportion as it is called forth. It is well, there- 

 fore, in applying galvanism for any purpose to the subject in whom the 

 action of life is suspended, to use the agent for one definite object, and 

 to remember that, in proportion as it is used, its power for good di- 

 minishes. 



Mechanical methods for restoring the circulation. In the last division 

 of the physical series of experiments, the object held in view was to set the 

 blood mechanically in motion through its own vessels. The attempts were 

 made (a) by forcing blood towards the right side of the heart and into 

 the lungs by the action of a syringe fixed in a vein, (b) by trying to draw 

 over a current of blood into the arteries from the veins and over the lungs, 

 (c) by trying to inject the heart of one animal with blood derived from 

 another animal. 



Forcing-action by the veins. A priori it seems an easy task to take an 

 animal so soon as it is dead, to fix a tube from a syringe in the external 

 jugular vein, to fill the syringe with blood, and by a downward stroke to 

 push on the blood in the course of the circulation. From a mechanical 

 point of view, the operation is perfect in theory ; and when we remember 

 that the auriculo-ventricular valve of the right side becomes in fact a natu- 

 ral valve for the piston, it is difficult to see how an artificial circulation can 

 fail to be established by this simple means. When we further remember 

 how easy it is to combine artificial respiration with the propelling process, 

 one must feel that, prior to a point of time when the blood has coagulated, 

 the process ought to succeed. Indeed, when the suggestion first occurred 

 to me, I was so struck by it, that I rose from bed in the middle of the night 

 to carry it out. Without for a moment losing faith in it, it has not as 

 yet, however, been successful in my hands. The practical difficulty lies in 

 the adjustment of the force employed. If too much force be used, the 

 vein gives way ; if too little, the obstruction in the pulmonary artery and 

 lungs is not overcome. In further researches I shall employ larger ani- 

 mals than I have done up to the present time. 



Suction-action by the arteries. While conducting this forcing-process 

 for artificial circulation, another idea suggested itself, viz., that perhaps it 

 would be possible to draw a current of blood over the lungs into the arte- 

 ries, oxidizing the current as it passed by artificial respiration. With this 

 object in view, a syringe, connected with an air-pump, was fixed in a large 

 artery, and the barrel of the syringe was then exhausted. When the 

 syringe was thus filled with blood, the motion of its own piston downwards 

 pushed the blood back into the arteries in the directiou of the heart. The 



