3dt2 Trowbridge — Electric Discharges through Hydrogen. 



By means of a side adjunct, a thermopile, T, was introduced 

 in order to measure the heat excited by the reflection of the 

 cathode rays passing through the diaphragm D and being re- 

 flected from the lamina, when the latter was inclined to the 

 axis of the cathode rays at varying angles. Here also there 

 was an action similar to the reflection of a stream of liquid 

 from the lamina, proceeding in the direction of the cathode 

 rays. The angle between the normal to the lamina and the 

 axis of flow or discharge could vary largely without affecting 

 the amount of heat from the reflected cathode beam, shown by 

 the thermopile. 



Striae. 



The striae, or stratifications in G-eissler tubes, constitute a very 

 beautiful and mysterious phenomenon of the discharge of elec- 

 tricity through gases, and if one could follow perfectly the 



Fig. 2. 



Fig. 2 represents an apparatus by means of which two pistons driven by 

 a motor in opposite directions cause waves in a trough filled with water. 



mechanism involved one could feel sure of having penetrated 

 far into questions of the method of propagation of electricity. 

 There seems no reason to doubt that the striae are phenom- 

 ena of ionization ; but the regularity of the striae leads one to 

 ask if this regularity could arise from some pulsation or rhyth- 

 mical action— the ionization being, so to speak, on top of such 

 rhythmical action. When the striae are excited by a storage 

 battery they are perfectly steady, and when it is certain that 

 there are no breaks in the circuit a telephone introduced into 



