24 



INJURY, RECOVERY, AND DEATH 



with mercury and into which dip copper wires, C, 

 which go to the Wheatstone bridge. These tubes are 

 contained in electrode holders of hard rubber, D, 

 through which pass a rod, E, and a long screw, F, 

 by means of which the electrode holders may be drawn 

 toward each other and held firmly in any desired posi- 



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1 



FIG. 3. Apparatus for determining the electrical conductivity of living tissue. The disks 



of tissue, L, are packed together like a roll of coins. At each end is a platinum electrode, A, 



fastened in an electrode carrier, D. By means of the screw, F, the electrode carriers can be 



drawn together, compressing the tissue and holding it firmly in place. 



tion. This screw engages an internal screw contained 

 in the electrode holder at the right. This is not the 

 case with the electrode holder at the left in which the screw 

 passes through a sleeve, and in consequence this electrode 

 holder is drawn toward the other only when the block, 

 M 9 is fastened in place by the set screw, N, and the 

 screw, F, is turned in the proper direction. 



An end view of an electrode holder, 7), is shown in 

 Fig. 4. Its lower portion (which contains the platinum 

 electrode) is shown inserted in a hard rubber support, 

 G. The support is pierced by a series of seven holes 



