PHARMACOLOGICAL ACTION OF TETRA-ALKYL-AMMONIUM COMPOUNDS. 31 



twelve seconds after the commencement of the injection. The paralysis 

 continued for nine seconds, and then quickly became approximately normal 

 for about six seconds, after which it became somewhat convulsive in type. 



The blood-pressure (104 mm. Hg) exhibited a transient rise, then a 

 fall to 77 mm. Hg. With the recommencement of the respiration a slight 

 transient rise occurred, followed by a fall to 39 mm. Hg, which was 

 maintained. 



Experiment IX. — Rabbit, decerebrate. Weight, 1800 g. Both fifth cranial nerves 

 cut, but left not completely. Anaesthetic stopped, 11.0. 



11.39. 1 mg. tetra-methyl-ammonium chloride injected. Respiration increased in fre- 

 quency three seconds after the beginning of the injection, but diminished 

 in extent, and four seconds later ceased. The paralysis lasted nine seconds, 

 then respiration recommenced and rapidly became efficient, the depth 

 being somewhat less than, but the frequency double, that before the injec- 

 tion. The increased frequency continued for two minutes, then gradually 

 passed away. 



The blood-pressure (73 mm. Hg) fell to 56 mm. Hg, and then com- 

 menced to rise with the complete cessation of the respiration and continued 

 until it reached 104 mm. Hg, just at the time when the respiration had 

 become well re-established. It then fell gradually to 70 mm. Hg at 11.41. 



Experiment X. — Rabbit, decerebrate. Weight, 1900 g. Both fifth cranial nerves cut. 



Anaesthetic stopped, 10.40. 



11.4. 1 mg. tetra-methyl-ammonium chloride injected. Respiration diminished in 

 extent five seconds after commencement of injection and was quickly 

 followed by increasing frequency and gradually increasing depth for eight 

 seconds. Then it diminished in extent and later increased until, forty- 

 five seconds after the injection, it was 30 per cent, more rapid and the 

 excursion of the lever was double that of the normal. Gradual return to 

 normal then occurred. 



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

 a prolonged fall, being 54 mm. Hg eleven seconds, and 40 mm. Hg two 

 minutes, after the commencement of the injection. At three and a quarter 

 minutes it was 49 mm. Hg, at six minutes 58 mm. Hg, and at thirteen 

 minutes after the injection 77 mm. Hg. 



11.20. 2 mg. injected. Increased rapidity of respiration commenced four seconds 

 after beginning of injection, but the curve gradually diminished in extent 

 until twenty seconds later it was only one-seventh its previous height. 

 The respiration then increased in extent, but diminished in frequency, 



