TROWBRIDGE. — DISCHARGES OF ELECTRICITY. 463 



ment. By means of a suitably placed diaphragm successive stages in 

 stratification can be produced. 



4. By modification of the form of discharge tubes rectification of 

 alternating discharges is possible. 



5. The Doppler effect in hydrogen is not modified by causing two 

 canalstrahlen to oppose each other. 



Jefferson Physical Laboratory, Harvard 



University, Cambridge, Mass., 



December, 1909. 



