Aortic Insufficiency. 



55 



from 106 to 87 minutes, and from 3 hours to 16 minutes. On 

 the other hand, similar tests of three cases of purpura brought 

 about no such result, the coagulation time remaining either the 

 same or being delayed by the fibrinogen. This was true likewise 

 when the fibrinogen was added to normal blood. 



There is a significant difference between the clot formation of 

 hemophiliac and normal blood. This can be clearly seen when we 

 compare the clots of the colorless oxalated plasma. The normal 

 clot shows a web composed of radiating threads of fibrin ; the clot 

 of typical hemophilia on the other hand is gelatinous and contains 

 a basic material resembling powder rather than fiber. 



In view of these results, it is concluded that there is a functional 

 deficiency, qualitative or quantitative, of fibrinogen in hemophilia. 

 This, however, does not seem to constitute the essential defect in 

 this desease, for the addition of fibrinogen was frequently not able 

 to bring the coagulation time to normal, nor does the local appli- 

 cation of fibrinogen to the bleeding point bring about effective 

 clotting. It is probable that a deficiency may be associated with 

 other pathological conditions. 



35 (967) 



Reflex vasodilation is not the cause of the collapsing pulse of 

 aortic insufficiency. 



By Carl J. Wiggers. 



[From the Physiological Laboratory, Cornell University Medical 

 College, New York City.] 



In 1908 Stewart 1 pointed out that the sudden rise and fall of 

 the pulse and the low position of the dicrotic notch, in short the 

 well-know "collapsing pulse" so frequently found in aortic in- 

 sufficiency, could not be due to a regurgitation for (1) the rapid 

 fall occurred before the dicrotic notch and hence during systole 

 and (2) volume curves of the heart show that very little regurgi- 

 tation takes place in experimental lesions. The changes were 

 therefore attributed to a reflex vasodilation for (1) this would 



1 Stewart, Archives of Internal Medicine, 1908, I, 102. 



