262 



DR JAMES A. GUNN ON 



Doses of 0*001 grm. per kilo and 0"002 grm. per kilo (fig. 10) caused a rise of blood 

 pressure. Doses of 0'004 grm. per kilo and 0*008 grm. per kilo (figs. 11 to 14) caused 

 a preliminary fall, followed by a rise, with later again a fall of blood pressure. 



The rise of blood pressure is in the case of all doses accompanied by slowing of 

 the heart. The increase of blood pressure must therefore be due either to increased 



Table VII. — Experiment 32. 





Time. 



Dose 

 of 



Average 



Pulse 



Rate 

 of 



Respiration 



Notes. 





Harmaline. 



B.P. in mm. 



Rate. 



Respirations. 



Excursus. 





1.0 





104 



40 



12 



3 mm. 





1.0.50" 





102 



41 



13 



3 „ 





l.l 



001 grm. per kilo 













1.1.20" 





106 



35 



11 



3 mm. 





1.2 





105 



29 



11 



3 „ 





1.3 





102 



29 



10 



3 „ 





1.9 





107 



31 



11 



3 „ 





1.11 





106 



32 



10 



2 





1.12 



002 grm. per kilo 











Fig. 10. 



1.13 



... 



lib 



27 



9 



2 mm. 





1.14 





110 



24 



9 



2 „ 





1.16 



... 



110 



26 



9 



2 „ 





1.21 





114 



26 



8 



91 



*~2 » 





1.25 



... 



114 



30 



8 



2i ,, 





1.29 



... 



112 



28 



7 



2A 





1.30 



0004 grm. per kilo 













1.30.30" 



... 



108 



26 



7 



2 mm. 





1.31 





116 



24 



7 



2 „ 





1.33 





112 



24 



6 



91 



z 2 >» 





1.35 





106 



26 



7 



2 „ 





1.39 





105 



26 



7 



9 





1.42 



... 



105 



26 



7 









1.44 





106 



25 



7 



2 „ 





145 



008 grm. per kilo 











Fig. 11. 



1.45.30" 



... 



76 



20 



4 



1 mm. 





1.46 





76 



18 



6 



1 „ 





1.48 





92 



19 



7 



1 



2 " 



Fig. 12. 



1.50 30" 





120 



20 



5 



i ,, 





1.52 





114 



20 



5 



i „ 





1.56 





100 



21 



7 



n ,, 





1.59 





101 



20 



6 



9 





2.6 





108 



21 



7 



3 „ 





2.8.10" 





109 



20 



7 



25 „ n 



Anaesthesia incomplete. 



2.9.40" 





119 



20 



7 



7 ., ?J 



Fig. 13. 



2.22 





102 



18 



6 



2 



Fig. 14. 



Experiment discontinued. 



cardiac output per single beat or to contraction of the blood-vessels. Perfusions of 

 the frog's heart give no indication of augmented action of the heart, whereas a solution 

 of harmaline so dilute as 1 in 20,000 constricts the frog's blood-vessels. It is probable, 

 therefore, that the rise of blood pressure is due to contraction of the blood-vessels. 

 The fact that this rise of pressure tends to be gradual and persistent points to the 

 contraction of the blood-vessels being due rather to an action on the arterioles them- 



