Scientific Proceedings. 



6 7 



II. Bleeding Followed by Immediate Transfusion of Saline. 









Per cent. 



Elapsed 











of blood 



time between 











removed 



dosage 





Weight 



Dose per 



Amount 



(approxi- 



and 





of dog. 



kg. 



bled. 



mately). 



bleeding. 



Result. 



kg- 



c.c. 



c.c. 





hrs. 



(In hours after dosage.) 



7-3 



O.OIO 



200 



35 



22 



Died within 60 hours, 



3-6 



it 



"5 



5o 



Z% 



<< 



4-8 



<« 



120 



33 



3 



< > 



4-5 



«« 



no 



33 



4 



t « 



9.0 



14 



175 



25 



3 



u 



All the inoculations in the last two series were made subcuta- 

 neously. 



48 (191) 



The effect on the normal dog heart of expressed tissue juice 

 from hearts of dogs poisoned with diphtheria toxin. 



By J. J. R. MACLEOD and GEORGE W. CRILE. 



[From the Physiological Laboratory, Western Reserve University^ 



The injection of moderately large doses of diphtheria toxins 

 into animals is followed by no change in arterial blood pressure 

 until after the elapse of a certain latent period, varying from 24 

 hours in the rabbit to 2-4 days in the dog, when it begins to fall. 

 The fall in blood pressure, having once occurred, rapidly proceeds, 

 so that within a very short time the animal is dead (30 minutes in 

 the rabbit). Both vasomotor paralysis and cardiac failure are 

 responsible for the fall, although it is evident that the cardiac failure 

 is the more important as the immediate cause of death, since mere 

 isolation of the vasomotor center — as after spinal transection — 

 is not followed by such rapid cardiac failure. The vasomotor 

 paralysis of course accelerates the cardiac failure. 1 



Roily further found that isolation by Hering's method of the 

 heart of a rabbit just dying as a result of diphtheria inoculation 

 and its perfusion with blood from a healthy animal did not in the 

 slightest degree delay the failure. 



Although a certain amount of histological change seems 

 always to be present in the myocardium after death from the 

 inoculation of diphtheria toxins, yet it has been considered by 

 Roily and others as scarcely of sufficient intensity to account for 



1 Roily : Archiv fur expcrimentelle Pathologic und Pharmakologie (1899), xlii; 

 Romberg, Paessler, et al. : Deutsches Archiv fur klinische Medizin, lxiv. 



