TOMITIXG — [MUSCULAR WEAKNESS. 4G5 



^•lia priests from coarsely-pounded bark, from uliicli water 

 would extract the poison more slowly ; and if only allowed to 

 remain a short time in contact with the bark, the infusion 

 would be comparatively weak, while the dregs themselves 

 would yield up their active principle in the stomacli after 

 being swallowed, and thus have a much more powerful action. 

 The purging is due to the local effect of the ])oison on the 

 intestines, for it only occurred when the poison was given by 

 the mouth, and was never present wlien the drug was admin- 

 istered by subcutaneous injection. Vomiting, on the contrary, 

 occin-red as constantly when the casca was injected subcu- 

 taneously as when given by the mouth. Q'he vomiting after 

 subcutaneous injection of the drug is probably due to its being 

 carried with the blood to the stomach, and irritating the sensory 

 nerves of that organ in much the same way as when introduced 

 directly into it. The reason why we believe the vomiting to 

 be due to irritation of the nerves of the stomach rather than to 

 the action of the drug upon the vomiting centre in the medulla 

 oblongata, is that when the vagi nerves were divided in the 

 neck of one cat, a dose wliich would ordinarily have proved 

 fatal produced no vomiting, nor indeed any of the usual 

 symptoms. In other cases where vomiting occurred even after- 

 division of the vagi, it was less tliau usual, and it might be due 

 to the irritation being convc^yed from the stomach to the 

 medulla by branches of the solar plexus instead of by the vagi. 

 The purging is probably due to increased peristaltic action rather 

 than to increased secretion, for infusion of casca introduced into 

 a loop of intestine produced no increased secretion, as a solution 

 •of sulphate of magnesia would have done. 



Muscular Weakness. — Want of power to walk properly is the 

 second symptom regarded as a proof of guilt in those subjected 

 to the ordeal, those who stumble before they reacli the end of 

 the archway of boughs being at once executed. In attempting 

 to ascertain tlie cause of tliis loss of powder, we worked back- 

 wards thus : The motions of the limbs are due to the contraction 

 of muscles. The contraction of muscles is due to the stimuli 

 they receive from motor nerves. The stimuli which ]3ass 

 <iown motor nerves to muscles ])roceed from nerve-centres ir 



2 H 



