PHARMACOLOGICAL ACTION OF TETRA-ALKYL-AMMONIUM COMPOUNDS. 493 



ammonium chloride, from hypertonic (17 per cent.) to one-tenth this strength, with 

 practically uniform results. Only on few occasions with the diluter solutions was a 

 slight, almost inappreciable, contraction obtained. In all cases the corresponding 

 muscle of the opposite side, which had been allowed to soak in a normal saline 

 solution for some time, gave, when treated with the same percentage solution of 

 tetra-methyl-ammonium chloride, a marked contraction. The preparation and 

 arrangement of the muscle from the time of pithing occupied about ten minutes, and 

 it was thought that the slight drying of the muscle occurring during the manipula- 

 tion might be the cause of this negative result, especially as a good contracture was 

 obtained by treating the gastrocnemius in a similar manner ; but this factor, although 

 probably important, does not afford the whole explanation, since a sartorius steeped 

 in 0'6 per cent, sodium chloride solution for seventeen minutes and then allowed to 

 dry for half an hour, at the end of which time it appeared much drier than the 

 muscles freshly excised, gave a good, although much less than normal, contracture on 

 immersion in a tetra-methyl-ammonium chloride solution. Moreover, a sartorius 

 immersed in a solution of a non-electrolyte — a solution of mannite was used — also 

 showed no contracture when subjected to the action of tetra-methyl-ammonium 

 chloride solution. In these cases the muscle when stimulated with a moderately 

 strong faradic current (secondary coil at 12-14 cm. or 600 Kronecker units ; one 

 accumulator cell) previous to immersion in the tetra-methyl-ammonium chloride 

 solution, failed to contract ; but contraction was sometimes obtained with the strongest 

 stimulus the coil would give. If the strength of the tetra-methyl-ammonium chloride 

 solution be not greater than 0'3 per cent., continued immersion is followed by the 

 appearance of irritability, often as marked as in a muscle immersed in Kinger's 

 solution. The irritability afterwards gradually diminishes. Boehm * remarks that if 

 the muscle — he worked with the semimembranosus and gastrocnemius — is not quite 

 fresh, if it has lain for half to one hour under moist filter-paper, contracture does not 

 occur. I have not observed complete absence of contracture in the case of the 

 gastrocnemius ; even when this muscle was allowed to remain in the moist chamber 

 three hours before being subjected to the action of a tetra-methyl-ammonium chloride 

 solution, a slight contracture was obtained. 



A few experiments were made to determine the time of immersion in 0'6 per cent, 

 sodium chloride solution necessary to produce the maximum contracture of a sartorius 

 subjected to the action of tetra-methyl-ammonium chloride. This was found to be 

 at least ten minutes. The extent of the contracture obtained with an isotonic solution 

 of tetra-methyl-ammonium chloride after immersion of the muscle for one minute in 

 0'6 per cent, sodium chloride was 1 mm. (the contracture being multiplied five times) ; 

 after four minutes' immersion in the same normal saline, the same strength of tetra- 

 methyl-ammonium chloride solution produced in the corresponding muscle of the 

 opposite side a contracture 1 1 mm. in height. The extent of the contracture usually 



* hoc. cit. 



