164 



Dr. C. B. RadclifFe on Electroscopic [May 31, 



tlie movements being only those of i. d. = 2 in both electroscopes 

 equally. 



Exp. 14. — The cerebellum of a sheep was examined in this experiment, 

 and the result was — no alteration in the divergence of the gold leaves in 

 the negative electroscopes, and i. d. = 4 in the positive electroscopes, a 

 state of things indicating the action of positive electricity = 2 upon the 

 instruments. It was ascertained also that all parts of the cerebellum in- 

 differently behaved in the same manner. 



Exp. 15. — In this experiment the brain of a donkey just killed by loss 

 of blood was examined, and it was found that all parts of the surface indif- 

 ferently, natural or artificial, gave similar indications of negative electricity 

 = 4, there being d. d. = 2 in the positive electroscope, and i. d. = 6 in 

 the negative electroscope. 



Exp. 16. — The brain of the donkey used in the last experiment was used 

 also in this instance, an interval of an hour, or thereabouts, having elapsed 

 between the two experiments. When first examined this organ gave indi- 

 cations of negative electricity = 4 ; now it was found to have lost all traces 

 of electrical activity everywhere, for the movements of the gold leaves were 

 simply those of i. d. = 2 in both electroscopes equally. 



These experiments, as I believe, bring to light a new fact, inasmuch 

 as they furnish the first electroscopic proof of the presence of electricity in 

 living nerve-tissue. Judging from these and several other experiments of 

 the same kind, in which dogs and rabbits, as well as oxen, sheep, and don- 

 keys, were put under contribution, it would seem that living nerve-tissue, 

 as a rule, furnishes electroscopic signs of electricity, sometimes positive and 

 sometimes negative in character, and that these signs are always absent 

 when the nerve-tissue may be supposed to have lost all traces of vitality. 

 And this also would seem to be a conclusion deducible from the same 

 evidence — that all parts of the nerve-tissue present signs of the same 

 kind of electricity. It would ^eem, in fact, as if these experiments sug- 

 gested a conclusion which is at variance with a conclusion drawn by Pro- 

 fessor Du Bois Reymond from some of his experiments. Watching the 

 direction of the "nerve-current" which passes through the galvanometer 

 between the longitudinal surface, natural or artificial, of the nerve-fibres, 

 and the transverse sectional surface of these fibres. Professor Du Bois 

 Beymond comes to the conclusion that these two surfaces are in oppo- 

 site electrical conditions, the one being positive, the other negative. 

 Because the current passes in a particular direction, he infers that these 

 surfaces must be electrified with different kinds of electricity. But 

 it is plain that the current might pass between parts electrified with 

 different degrees of the same electricity ; and indeed M. Du Bois Bey- 

 mond himself explains the current passing between two points of the same 

 surface in this manner ; and therefore, even on his own showing, there is 

 no necessity to suppose that the longitudinal surface of the nerve-fibres is 

 electrified with one kind of electricity and the transverse sectional surface 



