The Action of Nicotine and other Pyridine Bases upon Muscle . cle. 341 commercial curare was required for the complete curarisation of anaverage sized frog (20 to 30 grammes); a similar effect, on a similar frog, wasproduced in a shorter time by the same volume of a 001-per-cent. solution ofBoehms preparation.* The latter was thus known to be upwards of 100times as active as the commercial product, as judged of by its specific actionas regards blocking of the impulse from nerve to muscle. As regards direct effects upon muscle, both preparations of curare werewhat we are accustomed to call slig
The Action of Nicotine and other Pyridine Bases upon Muscle . cle. 341 commercial curare was required for the complete curarisation of anaverage sized frog (20 to 30 grammes); a similar effect, on a similar frog, wasproduced in a shorter time by the same volume of a 001-per-cent. solution ofBoehms preparation.* The latter was thus known to be upwards of 100times as active as the commercial product, as judged of by its specific actionas regards blocking of the impulse from nerve to muscle. As regards direct effects upon muscle, both preparations of curare werewhat we are accustomed to call slightly active, in 01-per-cent. solutionthe contractility of muscle was not abolished in half an hour (fig. 8). Boehmscurarine in 01-per-cent. solution was rather more active than the solution ofcommercial curare at the same concentration (but considerably less activethan nicotine at 0*1 per cent, and even 0*01 per cent.); this difference ofactivity between the two samples of curare was much below the difference asjudged by the specific curarisation t Fig. 8.—Effect of curarine iodide, 1 per 1000, or 00024 n. (Boehm.) The A ntagonism of Nicotine by Curarine. Langley has pointed out the antagonism of nicotine by curare; ournicotine and curarine experiments are confirmatory of this antagonism, andbring out approximately a quantitative relation between them. We find byimmersing muscles in mixtures of nicotine and curarine solutions in whichthe proportion of N : C by molecules is varied from 2:1 to 160:1, thatthe typical nicotine effect is unfailingly abolished when 30 molecules ofnicotine are in presence of 1 molecule curarine. In this instance thenicotine was taken at n/500, well above the strength required fora characteristic effect, as, moreover, was indicated by a simultaneous controlexperiment. The curarine in the mixed solution was at the concentra-tion 7^/16000, far below a concentration at which curarine by itself canact upon muscle. As shown above, cu
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