1902.] 



the Question of Blaze Currents. 



219 



their absence as a sign of its cessation. For the solution of this 

 question, a few experiments were undertaken with other organs of the 

 frog, namely, liver, kidney, and ovary of freshly-killed animals. With 

 such specifically-surviving organs as liver and kidney one would have 

 especially expected to find the currents which are supposed to be a 

 sign of life. 



Experiments on Liver, Ovary and Kidneij. 



Only one out of all the experiments made gave a result which could 

 in any way be compared with that obtained from the eye. The other 

 preparations all gave electromotive effects which were often very con- 

 siderable, but which cannot be otherwise regarded than as polarisation 

 effects, since they varied with the direction of the exciting current and 

 were always opposed to it. The one experiment which formed the 

 exception can hardly be said to agree with the observations on the eye, 

 since, although the excursions were certainly always in one direction, 

 they varied enormously in extent, according to the direction of the 

 exciting current, the proportion being sometimes as much as 8 to 1. 

 Faradisation of the organs produced no result at all when the coil was 

 so arranged that the make and break shocks were of equal intensity. 



It seems to me no longer possible, after these observations, to regard 

 the appearance of " blaze currents " as a specific property of living 

 tissue. It is much more probable that they are to be considered as 

 special manifestations of certain epithelial tissues. 



Neither can the presence of exclusively polarisation effects be taken 

 as the sign of the death of a tissue, since these may occur alone in a 

 very pronounced manner in living organs, and in a few organs may 

 even represent the regular and typical effect to stimulation. 



In conclusion, it is my pleasant duty to thank Professor Gotch, in 

 whose laboratory these experiments have been carried out, for the 

 facilities afforded me. 



