Physiology. — “On the Action of the Novocain on the Tonus of 
the Skeletal Muscle’. By Dr. S. pr Borr. (Communicated by 
Prof. J. K. A. WERTHEIM SALOMONSON). 
(Communicated at the meeting of October 29, 1921). 
When a subcutaneous injection of 5 or 10 drops of 1 °/, novocain 
is administered to a frog, the muscles will soon become entirely 
atonic. The stimulus-threshold of the N. Ischiadicus is then still 
unchanged and likewise the sensibility of the skin. According to the 
hypothesis of Erich Meyer and L. Weiter this atony is due to 
intoxication of the accessory nerve-endings of Bourke. Arms and also 
LirJESTRAND and Magnus ascribe it to intoxication of the sensibility 
of the muscle. The experimentai investigation of Frank and his 
co-workers corroborate Meyer and Wetier’s conception. 
When Frank published his experience my inquiry bad been in 
progress for some time. It is known that a small dosis of nicotin 
applied at the ingress of the nerve, produces acontracture. In order 
to obtain this effect by acting on the muscle-substance a much larger 
dosis must be used (LaNeLmr). This result is not altered by a previous 
denervation: five weeks after cutting the N. Ischiadicus I succeeded 
in evoking contractures in denervated muscles on administration of 
a subcutaneous injection of a minimal dosis of nicotin. 
When I injected into an intact frog first 5 or 10 drops of 1 °/, 
novocain subcutaneously, a complete atony of the skeletal muscles 
ensued after 15 minutes. Subsequently 10 drops of 1 °/, nicotin were 
given subcutaneously, which did not engender a trace of a contracture. 
In another series of experiments I injected into the muscles of 
the hind-leg 3 drops of 1°/, novocain to 1 cc of NaCl 0.65 °/,, by 
which these muscles lost their tonus. I then administered 10 drops 
of 1°/, nicotin subcutaneously; the muscles of three limbs then 
displayed marked contractures; those of the hind-leg that had been 
poisoned with novocain remained quite flaccid. Similar experiments 
were carried out with a foreleg. The result was the same when | 
injected into the muscles of one of the non-poisoned limbs only 
0.65 °/, NaCl solution. 
When the excised rectus abdominis is placed in 40 gr. of NaCl 
0.65 °/, and 1 drop of 1°/, nicotin is added, a marked contracture 
will ensue. This will not take place, however, when first 40 gr. of 
NaCl 0.65°/, +4 gr. of 1°/, novocain is allowed to act-on it for 
20 minutes, 
