68 Society for Experimental Biology and Medicine. 



the sudden failure. Furthermore, addition of diphtheria toxins 

 even in very large dosage to the fluid perfused through a Langen- 

 dorff heart preparation does not influence the beat ; nor does its 

 perfusion with the blood of a moribund animal (from diphtheria 

 inoculation). 



It has been suggested, therefore, (by Roily, et al.) that the 

 cardiac failure is due to a functional change resulting from the 

 gradual assimilation of toxin by the cardiac muscle until so much 

 had been taken up as to paralyze the muscle. Hence, the long 

 latent period and the rapid course of the failure. 



From a consideration of the findings it seemed to us possible 

 that, if any such compound of cardiac muscle substance and toxin 

 were present in the heart, its presence could be revealed by 

 expressing the tissue juices of the heart of a dead or dying dog 

 after inoculation with diphtheria toxins, and then adding this 

 extract to the blood perfused through a normal Langendorff heart 

 preparation. A large Buchner's press was employed by us for 

 preparing such extracts. It was found as a result of the injection 

 of such an extract into the heart that exactly the same result is 

 obtained as when a similar extract of the heart of a normal dog is 

 employed; viz., a sudden and complete inhibition of the beat fol- 

 lowed within a minute by marked fibrillation. It was found 

 impossible by any of the numerous methods recommended to re- 

 move this latter condition. 



A similar result was obtained by injecting a watery solution of 

 the ash of the extracts (made up to the original bulk) so that there 

 can be little doubt that the large amounts of potassium which such 

 an extract contains is responsible for the result. It is, however, 

 somewhat difficult to explain in the same way the marked and 

 persistent fibrillation which occurs, for such is not usually observed 

 after injecting pure solutions of potassium salts. The sudden 

 cessation of circulation alone cannot explain it, else would fibrilla- 

 tion occur in vagus stimulation. 1 



'Gross: Archiv ftir die gesammte Physiologie (1903), xcix, p. 264; Eraun : Ibid. 

 (1904), ciii, p. 476. 



