48 
Antipyrine in 500 milligram doses has only a slight depressant 
action on the heart rate, but with the injection of larger amounts the 
slowmg became quite pronounced. The blood pressure is also mark- 
edly affected, being lowered to such a degree that neither the slowing 
nor the changes in the efficiency of the heart afford a sufficient 
reason for its depression. For instance, with a lessened amplitude of 
3 millimeters and a decrease in rate of only 10 beats per minute, 
fhe pressure fall after an injection of a 1 gram dose amounted to 58 
