28 PROFESSOR C. R. MARSHALL ON THE 



11.24. 2 mg. again injected. Respiration quickly depressed and paralysed for three 

 seconds, followed by quick recovery and subsequently increased frequency 

 and depth. 



The blood- pressure (70 mm. Hg) showed a very slight preliminary 

 rise, followed by a fall to 39 mm. Hg and a secondary rise to 66 mm. Hg, 

 and subsequent fall to 34 mm. Hg at 11.26. 



Experiment II. — Rabbit, decerebrate. Weight, 2100 g. Anaesthetic stopped, 11.30. 

 Very low initial blood-pressure (26 mm. Hg). 



11.44. 1 mg. tetra-methyl-ammonium chloride into right external jugular vein. 

 Slight gradual depression of respiration and then (thirty-five seconds 

 after the injection) rapid paralysis. The blood- pressure gradually fell 

 to 11 mm. Hg. Artificial respiration was performed for three minutes. 

 The respiration was re-established, and the blood-pressure rose to 

 104 mm. Hg. 



11.52^. 1 mg. again injected. Rapid and almost complete paralysis of respira- 

 tion six seconds after commencement of injection with rapid recovery 

 eleven seconds later. The blood-pressure fell from 106 mm. Hg to 

 95 mm. Hg, and, after a transient rise to 102 mm. Hg, fell to 

 91 mm. Hg. 



Experiment III. — Rabbit, decerebrate. Weight, 2025 g. Anaesthetic stopped, 3.5. 



3.31. 1 mg. tetra-methyl-ammonium chloride injected. Rapid, shallow, and irregular 

 respirations almost immediately followed. Sixteen seconds later deep 

 convulsive respirations occurred and were replaced, after thirty -five seconds' 

 interval, by deep, regular respiration. 



The blood-pressure (80 mm. Hg) fell at first to 56 mm. Hg, and the 

 heart-beats diminished to less than half their previous frequency. Five 

 seconds before the commencement of deep breathing, the blood-pressure 

 commenced to rise, and rose to 123 mm. Hg. With the onset of good 

 regular breathing it gradually fell to 89 mm. Hg. 



3.37. 1 mg. again injected. Caused almost immediate paralysis of the respiration 

 followed by gradual recovery. 



The blood-pressure fell from 84 mm. Hg to 58 mm. Hg, and 

 the heart-beats from 13 to 5 in four seconds. The blood-pressure 

 then rose to 103 mm. Hg and the heart-beats to 6^ in four seconds. 

 At 3.39 the blood-pressure was 79 mm. Hg and the heart's frequency 9^, 

 in four seconds. 



3.45. A third similar injection produced the same effects, but these were accompanied 

 by marked muscular tremors. 



