TANTALUM BALKE 239 



used for electrolytic condensers and electrolytic detectors and pos- 

 sibly lightning arresters. 



Among other metals which have this property of valve action 

 more or less in common with tantalum are magnesium and aluminum. 

 However, owing to the ready susceptibility of both these metals to 

 chemical corrosion, they have not proved very suitable as sources 

 of direct current. Condensers and lightning arresters for high po- 

 tential transmission lines are commercially used with aluminum 

 plates. 



