OF THE CALABAR BEAN. 737 



15 minutes before poisoning, the right foot was drawn up in 13 beats. 

 10 „ „ left „ „ 11 » 



5 „ „ right „ „ 9 „ 



Two grains of extract, in 15 minims of water, were now injected into the subcutaneous 

 tissue of the back. 



In 5 minutes, the left foot was drawn up in 14 beats. 



22 



„ 36 „ the heart contracted per minute, 36 



28 „ 



j> 39 „ „ 18 



52 „ 



49 „ „ 18 



» 72 „ 



60 „ „ 17 



76 „ 



115 



10 



)> 



right „ 



15 



„ 



left „ 



20 



)i 



right „ 



25 



,, 



left „ 



30 



?? 



right „ 



35 



ji 



left „ 



40 



>) 



right „ 



45 



» 



left „ 



50 



)> 



right „ 



55 



>> 



left „ 



lh. & 



; min 



, right „ 



1 „ 



5 „ 



left „ 



1 ,. 



10 „ 



right „ 



1 „ 



15 „ 



left „ 



1 ,, 



20 „ 



right „ 



1 „ 



25 „ 



left „ 



1 „ 



30 „ 



right „ 



1 „ 



35 „ 



left „ 



88 „ „ 15 



99 } During this interval, the heart's impulse 



f could not be counted, but the frequency 

 i of its contractions was probably much 

 ■*■■'■■'- » ) lower than 15 per minute. 



138 „ the heart contracted per minute, 16 



169 „ 



186 „ „ 20 



192 „ 



left „ twitched slightly in 230 „ „ 20 



After this, no reflex movement occurred when either foot was dipped in much stronger acid ; 

 but galvanism applied to the exposed sciatics caused vigorous movements, which occurred only in 

 the limb whose nerve was stimulated. The cardiac contractions, in half an hour, became as 

 frequent as twenty-five per minute ; and, on the following morning, the thorax was opened, and 

 rhythmical contractions were perceived, at the rate of twenty-four per minute. A microscopic 

 examination was at this time made of the web, and a circulation was discovered in its capil- 

 laries. 



A few experiments were undertaken in order to eliminate the possible effect 

 of Calabar bean on the motor nerves in producing this gradual depression of 

 reflex activity. 



Experiment XL. 



The femoral artery and vein in each posterior extremity of a frog, weighing 540 grains, 

 were ligatured, and the animal suspended by the lower maxilla. Both feet were simultaneously 

 dipped in dilute sulphuric acid (10 min. of oil of vitriol to 12 oz. of water); and the interval 

 between the contact and the resulting reflex movement was measured, as before, by the beats 

 of a metronome. 



15 minutes before the poison was injected, reflex movement occurred in 10 beats. 

 10 9 



f) 1 1 



I then injected three grains of extract, in ten minims of water, under the skin of the back. 

 In 10 minutes, reflex movement occurred in 28 beats. 

 20 „ „ 24 „ 



30 „ „ 71 „ 



