l88 CHAP. XVII. WIRELESS STIMULATION 



modifying influence of tonic condition and intensity of stimu- 

 lation will probably afford an explanation of the anomaly. 

 I now describe the effect of wireless waves on growth. 



Fig. 109. Effect of strong intensity of field in 

 retarding growth (Wheat). 



Record under condition of balance. 



The Wireless System 



For sending wireless waves, I had to improvise the 

 following arrangement, more powerful means not being 

 available. The secondary terminals of a moderate-sized 

 Ruhmkorff 's coil were connected with two cylinders of brass, 

 each 20 cm. in length ; the sparking took place between 

 two small spheres of steel attached to the cylinders. One 

 of the two cylinders was earthed, and the other connected 

 with an aerial 10 metres in height. At the receiving end 

 the aerial was connected by means of a thin wire with the 

 experimental plant growing in a pot, which was put in 

 electric connection with the earth (fig. no). The distance 

 between the transmitting and receiving aerial was about 

 200 metres, the maximum length permitted by the grounds 

 of the Institute. 



I describe a typical experiment on the effect of wireless 

 waves on the growth of a seedling of Wheat. The specimen 

 was mounted on the Balanced Crescograph, and the growth 



