PHARMACOLOGICAL ACTION OF TETRA-ALKYL-AMMONIUM COMPOUNDS. 



27 



were divided close to the Gasserian ganglia ; in one experiment the ganglia were 

 removed. The anaesthetic was then stopped. Cannulse were introduced into the right 

 common carotid artery and the right anterior facial vein, for the purposes of recording 

 the blood-pressure and injecting the substance respectively. The respiration was 

 recorded by attaching a phrenograph or one limb of the tracheal cannula to a recording 

 tambour. The time occupied by the injections, unless otherwise stated, was about 

 five seconds. 





Fig. 7. — Effect of tetra-methyl -ammonium chloride on respiration and circulation of decerebrate rabbit. 

 Both fifth cranial nerves cut. Letters as in fig. 1. x ^. 



Experiment I. — Rabbit, decerebrate. Weight, 2300 g. Anaesthetic stopped, 10.45. 



11.14. 2 mg. tetra-methyl-ammonium chloride injected. Almost complete and im- 

 mediate cessation of respiration for three seconds, followed by increased 

 depth and frequency for ten seconds, and succeeded by a second almost 

 complete paralysis lasting twenty-five seconds, then quick and good 

 recovery. 



The blood-pressure (62 mm. Hg) showed a transient rise to 78 mm. Hg, 

 followed by a moderately quick fall to 36 mm. Hg, with slowing of the 

 frequency of the heart, and then a moderately quick rise to 1 1 1 mm. Hg. 

 This rise, in turn, was followed by a gradual fall to 38 mm. Hg (at 11.18), 

 and the fall by a gradual return to the normal height. 



