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When allowing this weak nicotin solution to act on the nervous 
aequator of a gastrocnemius without novocain, a marked contracture 
will appear, which will not be the case when the solution is made 
to act on the conical end. In order to achieve a contracture then 
a much stronger solution is required. 
We conclude, therefore, that novocain can obviate contractures 
originating from the nervous aequator. 
After this I used some substanees that enhance the tonus, such 
as calcium-chloride and rhodan-sodium. For each of these I ascertained 
the weakened solution just yielding a distinct contracture of an excised 
skeleton-muscle. I then substituted the tenth part of such a solution 
by 1°/, novocain. A frog’s muscle was then submerged in it after 
the muscle had first been attached to a lever and after it had been 
for 20 minutes in 1 °/, novocain. 
NaCNS yielded similar results to those obtained with nicotin. The 
contractures occurring after CaCl,-poisoning, could not be obviated 
by a previous intoxication with novocain. Just as large doses of 
nicotin CaCl, would also yield contractures through an action on 
the tonus-substrate itself. 
When in a frog hemisection of the med. oblongata proximal to the 
exit of the Nervus VIII is performed, there results a typical forced 
position. The ipsolateral foreleg is bent and adducted. The foreleg on 
the other side is abducted in a stretched position. The hind-legs display 
similar positions, but they are less pronounced. The head and the 
trunk are turned to the side of the lesion. Now when _ injecting 
into the muscles of the stretched and abducted foreleg two drops of 
1°/, novocain to 1 ee. of NaCl 0.65°/, the stretched position persists 
(in an uninjured frog such an injection produces a complete atony 
of the muscles of the foreleg). It appears then that the stretched 
position is evolved by a tetanic contraction, sustained under the 
influence of the ordinary cerebro-spinal innervation. 
It appears, therefore, that an equally active dosis of novocain 
leaves the cerebro-spinal innervation intact, while the tonus of the 
skeletal-muscles is abolished by it. Now since novocain abolishes a 
muscle-contracture that has been evoked from the nervous aequator 
(receptive substance), we are justified in concluding that the tonus 
of the skeletal-muscles is destroyed by novocain through a poisoning 
of the receptive substance of the tonus-substrate. Moreover it\ has 
been proved once more that in the skeletal-muscles two kinds of 
contractions can be evoked, viz. clonic and tonie contractions. 
