354 SIR THOMAS R. FRASER AND MR ALISTER T. MACKENZIE ON 



respirations were 11 per 10 seconds, irregular in time and amplitude, and the flank 

 respirations were 3 per 10 seconds and deep ; and the nose reflex was dull, the conjunctival 

 reflex almost gone and the sacral reflex absent. The frog would now remain quietly 

 on its back for 10 seconds ; it jumped feebly and clumsily ; and the pupils, which were 

 dilated before the injection, were now contracted. 



In 1 hour 30 minutes after the injection, there were no throat or flank respirations 

 seen in 60 seconds, but occasionally a single throat respiration occurred at longer 

 intervals ; the conjunctival reflex was almost absent ; the thorax was raised off the tray, 

 the fore-limbs being extended and parallel ; the frog jumped with difficulty ; and when 

 the posterior extremities were extended passively, they were not drawn up, and when 

 laid on its back the frog made no effort to recover. One hour 40 minutes after the 

 injection, examination of the web under the microscope showed that the circulation 

 had ceased. One hour 50 minutes after the injection, the heart was exposed. It was 

 motionless; the auricles were large and dark; the ventricle was moderately contracted but 

 not very pale, and none of the heart's chambers responded to mechanical or electrical 

 stimulation. When the skin of the abdomen was pinched, there followed a general con- 

 traction of the muscles of the abdomen and posterior extremities. 



(b) Experiments on Warm-blooded Animals. 



(1) Rats. 



Experiment XIX. — 0*041 gram of extract was injected subcutaneously into the 

 left flank of a male rat of the weight of 205 grams (equivalent to 0"2 gram per 

 kilogram, or f of minimum-lethal dose). Before the injection, the respirations were 27 

 per 10 seconds and regular; and the animal was alert. One hour 40 minutes after 

 the injection, the respirations were 27 per 10 seconds, regular, heaving and of greater 

 amplitude ; and the rat was drowsy and lethargic, and when disturbed, its movements 

 were unsteady. 



In 5 hours after the injection, the respirations were 25 per 10 seconds, regular and 

 heaving ; the cardiac impacts could not be felt, and when the animal moved about the 

 tray its gait was unsteady, and there appeared to be general muscular tremors 

 accompanying voluntary movements. In 22 hours after the injection, the respirations 

 were 27 per 10 seconds, regular and slightly heaving in character, and the rat was 

 sitting quietiy in a corner and showed no signs of uneasiness, but when disturbed, he 

 ran well and seemed mentally alert. 



Twenty-four hours after the injection, the respirations were 40 per 60 seconds, and 



irregular in time ; and at regular intervals there occurred sudden respiratory spasms, 



during which the thorax was fixed and the head was jerked forwards in an abrupt manner 



—a condition which lasted for about three minutes, after which the rat sat quietly in 



the tray. 



