38 GENERAL PROPERTIES OF LIVING TISSUES 



brings it again into contact with the iron. This 

 play is repeated until the chromic acid is all 

 reduced to chromic sulphate. 



rig. 5. Stage electrometer; 1 about three-sevenths the actual size. A, 

 Side view. B, Front view. 



The Electrometer. The electrometer consists of 

 a vertical tube drawn out at the lower end into a 

 fine capillary arid filled with mercury. (Fig. 5.) The 



1 Science, 1905, xxii, p. 602. 



