BY C. J. MAUTIN AND PRANK TIDSWELL. 493 



The cannula in the external jugular vein was used to introduce 

 the solution of the gland-secretion. This was dissolved in a -75% 

 solution of common salt, and was of such strength that 1 ccm. 

 contained 0-01 gramme of our dried secretion. Having started 

 our smoked paper travelling, and arranged the respiratory and 

 blood pressure records, we first allowed the apparatus to run in 

 order to obtain a portion of record previous to the introduction 

 of the solution. Of the solution 6 ccm. ( = 0-06 gramme) were 

 then rapidly introduced through the external jugular vein. 



Within three seconds from the commencement of the injection, 

 the blood pressure, which was previously equal to 97 mm. of 

 mercury, fell almost vertically to 60 mm. (mercury), when the 

 heart beats were seen to become much less frequent. At the 

 same time the respiration became hurried and exaggerated, and 

 speedily terminated in a series of expiratory convulsions. The 

 appearance was exactly the same as if one had clamped the wind 

 pipe and so asphyxiated the animal — only much more rapid in its 

 onset. During this convulsive period the blood pressure rose 

 again, even higher than before the injection, but speedily fell 

 again to within 27 mm. of the abscissa. By this time — 90 sees, 

 from the time of injection of the solution — the records of the 

 heart's beats disajjpeared from the tracing and the respiration 

 had ceased. A post mortem examination was immediately made. 

 The heart was still bea,ting feebly and continued so to do when 

 removed from the body. The right chambers of the heart, and 

 the whole of the venous system were discovered to be full of 

 clotted blood. The left cavities of the heart and the pulmonary 

 veins contained fluid blood, and there was an extensive subendo- 

 cardial hiemorrhage in the left ventricle. This result might 

 perhaps have puzzled us had we not had numerous opportunities 

 of witnessing precisely the same results after the introduction of 

 the venom of the Australian black snake or tiger snake* into the 

 veins of dogs and rabbits. 



* C. J. Martin. "On some effects upon the blood produced by the injection 

 of the Australian black snake." Journ. of Physiology, Vol. xv. No. 4, 

 1S93. 



