BY C. J. MARTIN AND FRANK TIDSWELL. 495 



The blood pressure previous to the introduction of the solution 

 was equal to 108 mm. mercury ; the heart beats were 300 per 

 minute and the respirations 48 per minute. Of the solution 2cc. 

 were then introduced (-02 gramme secretion). 



The blood pressure fell suddenly to 55 mm., the heart beats t<j 

 228 per minute (PL xxxi.). The respirations were not altered in 

 frequency, but became slightly irregular. Fov 90 seconds the 

 blood pressure continued to fall steadily, notwithstanding the 

 heart's beats soon reached 300 per minute again ; they were, 

 however, much enfeebled. At the end of that time, the pressure 

 was 46 mm. A further dose of -02 gramme was then injected. 

 There was a very slight further fall of blood pressure (to 42 mm.) 

 and the heart's beats became reduced to 228 per minute again, 

 t5ie respirations also becoming irregular. 



From this time the fall in blood pressure was steeper (as marked 

 by the curve), so that at the end of 2| minutes from the com- 

 mencement of the experiment it was only equal to 26 mm. of 

 mercury. The heart's beats had by this time become practically 

 obliterated on the tracing, although the heart could still be felt 

 feebly beating. 



During this time the respirations had become irregular both in 

 frequency and depth, and gradually becoming weaker and weaker, 

 were finally reduced to occasional inspiratory gasps. 



In 26 minutes from the beginning of the experiment the animal 

 quietly died. 



A post mortem examination revealed nothing except haemo- 

 rrhages under the endocardium of the left ventricle of the heart. 

 The blood was not clotted in any of the vessels, and on being 

 drawn off coagulated much more slowly than normally, taking 1 2 

 minutes. 



These four experiments prove that the secretion of the crural 

 gland contains some body which is capable of exerting very con- 

 siderable toxic action when introduced into the body of rabbits. 

 In the section of this paper devoted to the consideration of the 

 composition of the secretion, we adduced evidence that it contained 



