EFFECTS OF ELECTRICAL WAVES 483 



only a fagon de parler if we continue to speak of waves 

 in this case, just as we might still designate a circle as an 

 ellipse. If sparks pass across, the length of the waves varies 

 with the capacity and the self-induction of the discharger. 

 With small spheres and a short spark discharge very short 

 waves (a few centimeters in length) can be obtained. 

 The next shortest waves with which we are acquainted are 

 the "heat-rays;" after these come the ' ; light-rays" which 

 act upon the eyes; and finally the ultra-violet rays. The 

 wave-length is of importance in the effect produced by each 

 of these waves, in so far as every wave-motion is most effect- 

 ive when it strikes a body which constitutes a resonator for 

 the given wave-motion. Under such conditions the energy 

 of the waves may suffice to cause the body "to vibrate 

 sympathetically." Definite relations exist between the 

 wave-lengths and the dimensions of a resonator, according 

 to which the resonators for light-waves must have almost 

 molecular dimensions, while the longer waves such as arise 

 in the discharge of a condensator correspond to larger 

 resonators. 



This fact becomes especially important for the theory of 

 life-phenomena. The basis of all life-phenomena are chemi- 

 cal and molecular processes. It is therefore probable a priori 

 that only such wave-motions will be able to call forth 

 immediate life-phenomena, the resonators of which have 

 molecular dimensions. Thus we see, indeed, that light- 

 waves produce a series of physiological effects. But we 

 also see that certain functions such as the chlorophyll 

 functions or the heliotropic effects, etc., depend on definite 

 wave-lengths. I conclude from this that the heliotropic 

 functions and the chlorophyll functions are dependent 

 upon molecules of different dimensions. The electro- 

 magnetic theory of light will perhaps enable us to deter- 

 mine the approximate, and later perhaps the absolute, 



