364 SIK THOMAS B. FBASER AND MR ALTSTER T. MACKENZIE ON 



From the foregoing experiments, it is evident that S. sarmentosus acts upon 

 the cardiac and the skeletal muscles ; there is also some evidence of an action upon 

 respiration and upon parts of the cerebro-spinal nervous system. In only one case 

 was an increase of salivary secretion observed, and it is noteworthy that fibrillary 

 twitches of the skeletal and cardiac muscles are not conspicuous symptoms in poisoning 

 with this species of Strophanthus. Gaping movements of the mouth and rubbing of the 

 mouth with the anterior extremities were not observed in the experiments on the general 

 effects, but such movements did occur in other experiments where about fifteen times 

 the minimum-lethal dose was administered subcutaneously. 



C. Action on the Cerebro-Spinal Nervous System. 



(a) Brain and Spinal Cord. 



In the experiments performed to determine the general effects of S. sarmentosus 

 in frogs, rats, rabbits and cats, restlessness and, in many cases, an increase of 

 alertness are evinced a short time after the administration, and, still later, the 

 general condition of the animal is one of quietude, while in rats there occurs distinct 

 drowsiness. In cats, vomiting, which is a conspicuous symptom, does not begin 

 until twenty or more minutes after subcutaneous injection. No experiments, however, 

 were made with the object of ascertaining how far these and other symptoms might 

 be due to a direct action on the brain. 



In experiments performed to ascertain the action of the extract on the spinal cord, 

 the brain of a frog was destroyed anteriorly to a line joining the posterior margins of 

 the palpebral apertures, and thereafter the iliac, femoral and epigastrico-vesical (Ecker) 

 arteries of one posterior extremity were ligatured. The arrest of the circulation was 

 ascertained by examining the web under the microscope. For electrical stimulation, 

 a Du Bois Raymond's apparatus and a single bichromate cell were used. With the 

 secondary coil at 120 mm., the current was just felt on placing the electrodes on the 

 tip of the tongue. 



When a dose of the extract not much exceeding the minimum- lethal dose was 

 administered subcutaneously, the effects on the nervous system were found to be too 

 slight to admit of accurate observations being made. Much larger doses were there- 

 fore given. 



Experiment XLV. — Half an hour before the injection of 0*003 gram of extract 

 subcutaneously into the left flank of a male frog (Rana esculenta) weighing 60 grams 

 ( = 0"05 gram per kilogram, or fourteen times the minimum -lethal dose), the vessels of the 

 right posterior extremity were ligatured, and both sciatic nerves were exposed. The 

 reflexes were found to be active, and the frog jumped well when irritated. Ten minutes 

 after the injection, stimulation of the web of either foot with the secondary coil at 120 mm. 

 caused the irritated foot to be slowly drawn away, and stimulation over the spinal cord 



