TENSION PHENOMENA OF LIVING ELEMENTS. 143 



The erythrocytes are practically impermeable to ions. Stewart 1 

 observed that they offered a great resistance to the electric 

 current. It is difficult to remove all of the serum from a mass of 

 ervthrocytes, but Bugarsky and Tangl, working independently 

 f.t" Mt -uart, obtained sediments of corpuscles having a conduc- 

 tivity of only 1/50 that of the serum. This indicates that the 

 corpuscles are practically impermeable to both classes of ions, 

 for it permeable to ions of one sign, they would probably not be 

 -mli good insulators. The electric conductivity of the a-h 



made up to equal volume) of the corpuscles is about that of the 

 -eriim, although the osmotic pressure of the solution of ash of 

 tin- latter i- greater. 2 



llrinr an increase in electric conductivity of tin- corpuscles 



as \\ill !> considered below) indicates increased prrmrabilit\ 

 ion- After the corpuscle becomes permeable to ion-, further 

 in. i. ase in conductivity might be due to liberation of ion- from 

 i . >ml 'iiiat i. nis with colloids in the interior. Howe\ IT many i< uis, 

 f. 'i in-tam . I'O^ cannot be liberated without incineration or other 

 rigorous treatment. Increase in conductivity of the blood by 

 lakii nts has been proven to be chiefly due to increased per- 



nieabilit\ o! the corpuscles, since the conduct i\ ity of the serum 

 m MI -ho\\s so great an increase on the addition of the 1. iking 

 in. ami is usually diminished (by the hicmoglobin if the cor- 

 pn-cles are present. 



The portion of the normal corpuscle presenting the greatest 

 resistance to the electric current is the surface layer, since I lol-r 

 ol.ser\ed thai the conductivity of 'the interior of tin corpn- 



.1. i rmine.l by its dielectric value) is many time- greater than 

 thai of the corpuscle as a whole. Peskind 1 cau-ed bubbles of 

 nitrogen to form \\ i thin the corpuscle and observed that they were 

 retained by a superficial membrane. This may be the membrane 

 \\liicli n-i-ts the electric current. 



The chemical composition of the corpuscle is suppo-ed to bear 

 .-ome relation to its permeability. Aside from the haemoglobin, 

 and the rather low water content (60 per cent.i the corpuscle 

 ' S< .'-'.'. - . J.ni. a, 1897. 



M.Mirr.m'l Ruaf. Biochcm. Jour., III., 155. 

 r -,.., \rch., 1910, CXXXIII.. 237. 

 1 .li. Jmtr. I'hysioL. VIII. 



