APPENDIX 



'25 



These experiments were performed with the apparatus shown in 

 Fig. 17, which was used on account of the difficulty otherwise experienced 

 of removing the coagulated albumin from curved tubes. The resistances 

 here include the polarization effect, and hence are higher than they should 

 be ; but an experiment performed by the differential method also showed 

 that the conductivity of egg-albumin is unchanged by coagulation. 



Egg-albumin containing water therefore conducts like a feebly saline 

 electrolytic fluid, and has a correspondingly high resistance. We may 

 safely conclude that the same applies to living protoplasm, in which also 



FlG. 17. Portion of apparatus for finding influence of temperature and of coagula- 

 tion upon the conductivity of egg-albumin. 



therefore the electrical resistance is partly dependent upon the velocity 

 of the charged ions, which again is dependent upon the viscosity of the 

 medium, water, through which they travel. The viscosity of water decreases 

 with rise of temperature, and hence the velocity of the ions increases. 

 A large portion of the increased conductivity is due to this cause alone. 



The coagulation of the albumin is, however, without effect upon the 

 viscosity of the water filling the intermicellar interstices of the coagulum, 

 and hence is also without effect upon its conductivity. It is evident, 

 therefore, that the mere coagulation of the dying protoplasm will not 

 explain its slightly increased conductivity, which is in fact probably due 

 to the liberation from it of electrolytic salts in the act of death these 

 being present in living protoplasm in smaller amount in the free condition. 

 The same explanation possibly also applies to the fact that the conductivity 

 of stale egg-albumin is somewhat greater than that of fresh samples, even 

 although the percentage of water is the same in the two cases. 



A thread of egg-albumin of i cm. in length and 01 cm. diameter 

 (-0000785 sq. cm. sectional area), would offer a resistance of nearly 



