( 558 ) 
The faculty of nicotine to cause tonic contraction of muscles, has 
been amply studied by Langley in his experiments on receptive 
substances 1 ). The forelegs of the frog, the flexors of which are so 
easy to bring in tonus, also by dripping with nicotine, would have 
been very fit for our purpose, if not the mass of the available 
muscles was so small that for a single determination of creatine a 
large number of frogs would be necessary. The experiments of 
Langley, however, made us surmise that also the hindlegs would 
be fit for our purpose, which surmise was corroborated by the result. 
First an experiment was made as follows: 
After destroying brain and spinal cord 1 CC of a 1 7 0 -solution of 
nicotine in Ringer’s solution was injected into the abdomen, after 
which the tonic contraction of the forelegs soon made itself manifest. 
Half an hour after the injection the current of blood, by section of 
the heart, was brought to a standstill. Now the left ischiadicus was 
laid bare in the upper part of the thigh, cut through and for 
half an hour stimulated 24 times per minute with induction-strokes. 
Till the end the muscles reacted upon the stimulation of the nerve 
and at last a slight rigour was to be observed. 
The stimulated muscles produced 3.491 mgr. of creatinine per 
grm. of muscle, the non-stimulated 3.090 mgr. Difference 0.401. 
Then the experiments were made in the same way as with vera- 
trine, with the following result: 
Ringer’s sol. Nicotine. Difference. 
(1 : : 100 ) 
I 3.286 3.766 0.480 
II 3.090 3.492 0.402 
(1: : 200) 
III 3.276 3.538 0.262 
(1 :100) 
IY 3.037 3.401 0.364 
At the end of the experiment the leg immersed in nicotine did 
not visibly contract any more and each time this leg was some¬ 
what stiff. 
Through an examination of the action of kalium- and calcium-salts 
also Guenther 2 ) has come to the result that the muscular fibre 
possesses contractile substances of two kinds, one of which is made 
more susceptible to stimulation by K, the other by Ca. 
1) Journ. of Physiol. Vol. XXXIII, p. 374, Vol. XXX VI, p. 347, Vol. XXXVII, 
p. 165, p. 285, Vol. XXXIX, p. 235. Proc. Royal Soc. B. Vol. LXXVUI, p. 170 
2) Amer. Journ. of Physiol. Vol. XIV, p. 73. 
