18 PROFESSOR C. R. MARSHALL ON THE 



and their observations were corroborated by Rabuteau * and Brunton and Cash.1" 

 Later, Dufaux,| Santesson and Koraen,§ and Iodlbauer || showed that the same effect 

 was obtained with tetra-methyl-ammonium chloride. 



So far as I am aware, no experiments demonstrating this action on mammals 

 have been described. Rabuteau,H in the two experiments he made with tetra-methyl- 

 ammonium iodide on dogs, observed muscular paralysis as one of the symptoms ; and 

 Brunton and Cash,** after injecting 1 g. of the same compound into a rabbit, found 

 the animal lying apparently paralysed two minutes after the administration. When 

 half this dose was injected, they noticed the head falling to one side two and a half 

 minutes afterwards, but one and a half minutes later violent movements of the limbs 

 occurred. IoDLBAUER,tt working with the chloride, had similar experiences. The 

 animal usually fell on its side, and there were frequently convulsive movements and 

 later fibrillary tremors. Jacobj and Hagenberg|| also noticed muscular paralysis 

 after tetra-methyl-ammonium tri-iodide. But none of these observers appears to 

 have investigated the cause of the paralytic symptoms. 



My own experiments have been made on rabbits and cats during a state of 

 anaesthesia or after excision of the cerebral hemispheres. The rabbits were anaesthetised 

 with ether, or, in the case of animals to be decerebrated, with a mixture of chloroform 

 and ether ; the cats with chloroform followed by ether. The blood-pressure and 

 respiration were recorded, and one of the nerves supplying a fore or hind limb was 

 isolated and stimulated continually during an injection or intermittently before and 

 after an injection. The contraction of the limb was recorded by inserting a hook 

 into the limb and connecting this by thread working over pulleys to a writing lever. 

 This method of recording; the contractions of the limb was found better for the 

 purpose in view than that of recording the contractions of individual muscles, 

 probably owing to less interference with the blood supply. The injection of the 

 substance was made in the case of rabbits into the right anterior facial vein and 

 in the case of cats into the right external jugular vein. 



Both in rabbits and cats the intravenous injection of 0'5 to 1 mg. p. kg. body- 

 weight diminishes the excitability and often paralyses the motor nerve-endings, the 

 muscles themselves still retaining their irritability, over the whole of the body. 

 Rabbits seem to be somewhat more susceptible than cats, but otherwise the effects 

 on the two animals are identical. When the injections are made into the facial or 

 external jugular vein, the muscles of the fore part of the body are earliest and most 

 markedly affected. After a dose of 1 mg. p. kg. moderately quickly injected, the 

 nerve endings in these muscles are more or less paralysed within ten seconds of the 

 commencement of the injection, and in susceptible animals may remain paralysed for 

 several minutes. Fairly quick recovery then occurs. 



* ComjA. rend., lxxvi. p. 887 [1873]. t Trans. Roy. Soc. Lond., clxxv. p. 215 [1884]. 



X Dissert. Berlin., 1888, quoted by Santesson and Koraen, p. 220. 



§ Skand. Arch./. Physiol., x. p. 220 [1900]. || Loc. cit., p. 185. IT Loc. cit. 



** Loc. cit., p. 209. tt Loc. cit., p. 189. %% Arch.f. exp. Path. u. Pharm., xlviii. p. 48 [1902]. 



