1906.] Recently -Discovered African Arrow Poison. 



29 



the first two falls, the pressure shooting up 60 and 40 mm. Hg respectively. 

 The last fall was practically to the lowest point of the curve, and the heart 

 only recovered itself by 10 mm. Hg before ceasing as the pressure fell to its 

 lowest point of 20 mm. Hg above zero. It will be seen that the respiratory 

 rhythm of the blood pressure becomes lost towards the end. 



Heart Beats. — The rate of the heart was 213 per minute before injection- 

 Until the pressure rose there was no alteration in the rate. During the first 

 rise of pressure the heart beats became rather slower as the summit of the 

 ■curve was reached ; the number of beats during the 10 seconds of the first 

 rise was 33, making a rate of 198 per minute. The beats also became rather 

 larger. During the first fall of pressure, which lasted six seconds, 

 16 pulsations occurred, making a rate of 160 beats per minute, the pulsations 

 also became larger. 



During the second rise of pressure the heart became gradually more and 

 more rapid as the summit of the curve was reached, the rate at this point 

 being 216 per minute. At the first part of the rise the pulsations were very 

 irregular in size ; towards the end they became much smaller as the rapidity 

 increased, and they were also irregular. During the second and final fall of 

 pressure the pulsations were very rapid and small, and towards the end were 

 uncountable, the curve being practically a straight line. 



Respirations. — The respiration was unaffected till the blood pressure fell to 

 its lowest level, when five large inspirations were taken, inspiratory gasps 

 following at intervals for the next 104 seconds, the blood-pressure curve 

 meanwhile forming a straight line at about 20 mm. Hg above zero. 



Experiment 2. — Cat, weight 1950 grammes. Poison 1/12 gramme 

 (= - 042 gramme per kilogramme). 



Blood Pressure. — The first rise was very well marked, and commenced 

 immediately the injection was given, and the subsequent fall also, but the 

 .second rise was not seen, the pressure, after maintaining itself for a little 

 while, gradually dropping to its lowest point. 



The pressure before injection was 120 to 126 mm. Hg, and the first rise 

 reached its maximum point of 178 to 184 mm. Hg in 40 seconds. It was 

 154 to 164 mm. Hg 80 seconds later, and from this point it fell gradually to 

 its lowest point of 20 mm. Hg above the zero line. There were no sudden 

 falls of pressure as the curve was descending. The second rise in pressure, 

 as I have already mentioned, is due to some extent to the heart, and it did 

 not occur in this case, probably because that organ was unable to maintain 

 the pressure. The cat was not a strong animal, and it breathed somewhat 

 irregularly the whole time. The respiratory rhythm of the pressure curve 

 becomes lost towards the end. 



