iqoo-i.] 



Observations on Blood Pressure. 



195 



Hill and Barnard give a tracing^ showing the effect of abdominal 

 pressure. In it the pressure actually goes above the normal line, as it 

 also did in tracing 1 1 just given, and in order to get such a rise a large 

 amount of abdominal pressure must have been applied, and probably the 

 aorta was more or less completely obstructed by this. I tried the 

 tightening of an abdominal bandage as described by Mr. Leonard 

 Hill,-' but got almost negative results. Consequently I believe that 

 slight supporting of the abdominal walls by bandages can have little or 

 no effect upon the general blood pressure, and the comfort given by 

 such to a certain class of patients cannot be attributed to any 

 appreciable rise of blood pressure. One point, however, must be here 

 borne in mind, and that is that while in healthy animals the abdominal 

 wall is normal, in certain individuals it is abnormally flaccid. 



46 



Tracing XII.— 1/3. —Spinal cord previously divided at level of last dorsal vertebra. 44 Vertical. 

 45 Abdominal pressure. 46 Horizontal. 



Tracing 12 shows the effect of abdominal pressure on a vertical 

 animal in which the blood pressure was standing almost at zero on 

 account of previous division of the spinal cord. 



Tracing XIII. — 9/20. — Canula in distal end of fermoral artery, i Abdominal pressure. 2 Pressure 

 removed. 



Tracing 13 shows the effect of abdominal pressure on the blood 

 pressure in the distal end of the femoral artery. The animal being 

 horizontal, as seen the pressure slowly fell, which goes to prove that, as 



1 Tracing: 86, Journal of Physiology, Vol. XXI., 1897. 



2 "The Cerebral Circulation," p. 100. 



