226 



occupied, either ir» coiise(|nence of the experiruent oi' llirongh the 

 after-effect of emotional occurrences, the i-espiratorj oscillations dis- 

 appeared from the galvanogram, while in the case of still intenser 

 preoccupation other modifications in the level of the curve appeared, 

 which were independent of respiration. All these modifications in 

 the shape of the galvanic curve run parallel with the oscillations in 

 the level of the plethysmogram, either in the same or in the opposite 

 direction. Curve I is an illustration of the respiratory oscillations 

 in the galvanogram. 



The following objections may be raised to the hypothesis that 

 these oscillations are connected with the respiratory oscillations in 

 the equilibrium between the sympathetic and the parasympathetic 

 (vagus resp.) nervous system : 



a. The oscillations are effected by the movements of the respir- 

 ation-muscles. 



b. They are caused by the changes in the electrical resistance 

 which are brought about by rhythmic movements of the arm during 

 respiration. 



c. They are caused by the resj)iratory oscillations in the blood- 

 filling of the extremities. 



The first objection is done away with by the fact that in the case 

 of preoccupation the fluctuations disappear (curve II) whereas the 

 movements of the respiration-muscles continue. This phenomenon 

 might likewise tell against the second objection, just as the fact 

 that the subject always rested his hand on the bottom of the arm- 

 Baths, Hereby the movements of the upper-arm, which were already 

 none too vigorous at first, were considerably relaxed if not checked 

 entirely. However, with six subjects I have registered the movements 

 of the upper-arm with the aid of a very sensitive tambour affixed 

 to the arm-bath, its rubber membrane, which is provided with a 

 knob, resting on the m. biceps. Hereby it was proved that the move- 

 ments of the upper-arm do not affect the shape of the galvano- 

 gram. This is illustrated in Cnrve III where the movements of the 

 upper-arm are reproduced graphically ; of oscillations in the level 

 of the galvanic curve, on the other hand, no trace is to be seen. 

 Curve IV further shows that even considerably stronger involuntary 

 arm-movements do not alter the shape of the galvanogram. 



Finally, that the electric modifications in respiration cannot be 

 ascribed to the bloodfilling of the extremities is demonstiated by 

 curve V, which exhibits distinct respiratory oscillations of the galvano- 

 gram, although the extremities, from which current were derived, 

 had been made bloodless by bandaging. 



