32 PROFESSOR C. R. MARSHALL ON THE 



and twenty seconds later was almost normal. Afterwards it gradually 

 became slower and finally ceased five minutes after the injection. 



The blood-pressure (77 mm. Hg) showed a slight preliminary rise and 

 then a fall to 58 mm. Hg at ten seconds, and 49 mm. Hg at twenty 

 seconds after the injection. No recovery occurred. 



Experiment XI — Rabbit, decerebrate. Weight, 2450 g. Both fifth cranial nerves 

 cut proximal to Gasserian ganglia. Anaesthetic stopped, 11.20. 



11.36. 0'6 mg. tetra-methyl-ammonium chloride injected. Six seconds after com- 

 mencement of injection the respiration increased suddenly to three times 

 its previous frequency and about 20 per cent, in depth. This effect 

 was maintained half a minute and then commenced to pass away, but the 

 respiration had not reached its normal rate eight and a half minutes after 

 the injection. 



11.44^. 1 mg. injected. The earlier part of the effects of this injection is shown 

 in fig. 7. 



11.58. 1 mg. injected (took twelve seconds). Thirteen seconds after the commence- 

 ment of the injection there occurred a marked increase in the frequency 

 and a transient increase in the depth of the respirations, which soon 

 commenced to pass away. 



11.594- 2 mg. injected (took eleven seconds) while respirations still rapid. Increased 

 frequency and increased depth of respiration commenced three seconds after 

 the beginning of the injection and was replaced by slowing and diminished 

 depth five seconds later. After a further interval of five seconds the 

 respiration ceased. The paralysis lasted for thirteen seconds. When the 

 respiration recommenced, it was shallow and rapid, but it quickly reached its 

 normal form. There was marked slowing of the heart and a fall of blood- 

 pressure after the previous injection and a further slight slowing of the 

 heart and slight fall of blood-pressure after this injection. 



12.5^. 5 mg. injected. The effect is shown in fig. 7. Occasional shallow respirations 

 occurred afterwards. 



Experiment XII — Rabbit, decerebrate. Weight, 2200 g. Both Gasserian ganglia 



excised. Anaesthetic stopped, 3.38. 

 3.53. 0*5 mg. tetra-methyl-ammonium chloride injected. Gradual diminution in depth 

 of respiration commencing four seconds after beginning of injection and 

 reaching maximal diminution, which was maintained six seconds, ten 

 seconds later. Recovery gradually occurred during the next fifteen 

 seconds. 



The blood-pressure (65 mm. Hg) rose slightly and then fell to 

 45 mm. Hg nine seconds after the beginning of the injection, and to 



