30 



INJURY, RECOVERY, AND DEATH 



volving in a suitably arranged magnetic circuit such as 

 is furnished by Leeds and Nortbrup. The results so 

 obtained did not differ from those secured with a 

 Vreeland oscillator. 



Fig. 6. — Diagram te ahow bridge and connections. S ie an alternating eource (1000 cycle* 

 or more), A and B are the ratio arms of the bridge, C is the variable resistance of the bridge, 

 X is the unknown reslBtance (tissue and holder), Tj telephone, F, variable condenser, G, a 

 ground wire from the centre of a high resistance (in case the ratio arms of the bridge are 

 unequal the two parts of the high resistance should also be unequal) . 



The use of the ordinary lighting circuit (60 cycles) 

 with a vibration galvanometer is recommended by Green 

 (1917). The use of an alternating current galvanom- 

 eter in connection with a recording device is suggested 

 by Weibel and Thuras (1918). 



