943 



satisfactory results were obtained, comparable with those obtained 

 by means of a Frank- mirror-tambour. Different frequencies were 

 obtained by using 7 different interrnpters carefully adjusted to 10, 

 12, 14, 16, 18, 20 and 22 interruptions per second. 



With healthy persons all muscles showed a complete tetanus at 

 a rate of excitation with 20 interruptions per second. With 16 inter- 

 ruptions ull the curves showed the characteristic indentations or notches, 

 indicating the rests of the separate muscle twitches. With 18 per 

 second the behaviour of the different muscles showed slight diver- 

 gencies, some giving a complete tetanus, others still showing the 

 single twitches. As an example of a normal record we give fig. 1, 

 from the gastrocnemius of a healthy woman of 53 years of age. 

 We see 5 tetani obtained successively with J 2,14, J 6, 18, and 20 

 stimuli per second. In the curve taken with 18 per second, slight 

 oscillations may still be observed, whereas the last curve may be 

 considered, as a complete tetanus, though the first 2 or 3 stimuli 

 are still visible in the myogram. But this was frequently the case 

 and we considered a tetanus as a complete one when after the 

 3'd stimulus the oscillations were no "longer visible. 



If now these curves be compared with those of fig. 2, in which 

 the rate of stimulation was from 12 to 22 per second, we recognize 

 the oscillations even in the last curve, obtained with a frequency of 

 22 per second. These records are taken from the gastrocnemius of 

 a woman suffering from advanced locomotoi' ataxia. All the muscles 

 were in an extremely atonic condition. 



Lastly we reproduce in fig. 3 the record of faradic tetani of the 

 gastrocnemius at a rate of 12, 16, 18, 20, and 22 stimuli per second. 

 This patient was a man of 45 suffering from sclerosis multiplex 

 cerebrospinalis. All muscles were hypertonic and showed a tendency 

 to contracture. Even with no more than 12 stimuh per second we get 

 a complete tetanus. 



The few curves shown are taken somewhat at random from a 

 collection obtained in a large number of healthy persons and patients 

 with either hypertonic or atonic muscles. We always find that in 

 hypertonic muscles the critical fiequency is generally 14 or lower, 

 whilst in atonic muscles it is always well over 20. 



In the course of our researches we obtained many other interesting 

 records. A few showed a gradual fatigue or exhaustion of the tonus 

 mechanism. Others contained an indication, that under the influence 

 of the contractions an appreciable increase of the tonus occurred. 

 A more detailed description of the experiments and the results will 

 be published elsewhere. 



61* 



