30 PROFESSOR C. R. MARSHALL ON THE 



what in frequency. There was a simultaneous rise (occupying six seconds) 

 of blood pressure from 114 mm. Hg to 150 mm. Hg, and after maintaining 

 this level for twenty seconds it gradually fell. The effect on the respiration 

 continued somewhat longer than that on the blood-pressure. The frequency 

 of the heart was not affected. 



12.27. 2 mg. again injected. Respiration affected as after previous injection, but 

 increase in depth somewhat greater. The blood-pressure fell from 124 mm. 

 Hg to 102 mm. Hg for a few seconds, then rose to 156 mm. Hg, which 

 was maintained for twelve seconds. It then fell, at first quickly, afterwards 

 slowly, to 102 mm. Hg at 12.28|. 



12.29. 10 mg. tetra-methyl-ammonium chloride injected. Respiration completely 

 paralysed seven and a half seconds after commencing the injection. No 

 recovery occurred. 



Experiment VII. — Rabbit, decerebrate. Weight, 1850 g. Both fifth cranial nerves 

 cut, the right not completely, proximal to the Gasserian ganglia. Anaesthetic 

 stopped 10.50. 



11.21. 2 mg. tetra-methyl-ammonium chloride injected. Marked increase in depth of 

 respiration commencing six seconds after beginning of injection and lasting 

 four seconds and passing on to complete paralysis five seconds later. 

 Spontaneous recovery did not occur, and artificial respiration only estab- 

 lished infrequent respirations. 



The blood-pressure (96 mm. Hg) rose slightly and then fell rapidly to 

 56 mm. Hg. Afterwards it rose to 98 mm. Hg and then fell to near the 

 base line. 



Experiment VIII. — Rabbit, decerebrate. Weight, 1775 g. Left fifth 

 cranial nerve cut. Anaesthetic stopped, 11.30. 



11.59. 1 mg. tetra-methyl-ammonium chloride injected. The respirations trebled in 

 frequency a few seconds after the commencement of the injection, but 

 rapidly diminished in depth and ceased ten seconds after beginning the 

 injection. The paralysis lasted eleven seconds. After recommencing, the 

 respiration quickly became efficient and remained somewhat more rapid 

 although less deep for two minutes before gradually returning to normal. 



The blood-pressure (95 mm. Hg) showed a transient rise, then a quick 

 fall to 76 mm. Hg, which was succeeded by a slight rise and then a gradual 

 fall, concurrent with the recommencement of the breathing, to 56 mm. Hg. 

 Recovery to the normal took several minutes. 



12. 4£. Injection repeated with similar result. 



12.29. 1 mg. again injected. A few very powerful respirations almost immediately 

 followed, but the respirations quickly diminished in depth and ceased 



