160 



Dr. C, B. RadclifFe on Electroscopic 



[May 31, 



with negative electricity, and in which negative electricity produces increased 

 divergence of these leaves, as the Negative Electroscope. 



II. An account of experiments in some of which electroscopic indications 

 of animal electricity were detected by the method of experimenting which 

 has just been described. 



In this account the degree of movement of the gold leaves is indicated 

 by arbitrary figures. It is assumed also that the increased divergence of 

 the gold leaves in both electroscopes, which movement has been seen to 

 arise from the reaction of the charge of electricity in the electroscope, is 

 = 2; and in each experiment this figure is added to the movement pro- 

 duced by the action of free electricity in the case where this action causes 

 increased divergence of the gold leaves, and subtracted in the case where 

 this action causes diminished divergence of these leaves. Thus, in the 

 case where the movement of the gold leaves arising from the action of 

 free electricity is =3, the actual movement of the gold leaves in the 

 instrument in which there is increased divergence of these leaves will be 

 = 5, for 3 + 2 = 5, and in the instrument in which there is diminished 

 divergence of these leaves will be =1, for 3 — 2 = 1. Or, in the case 

 where the movement due to free electricity is =1, there will be a different 

 degree of increased divergence of the gold leaves in both electroscopes ; 

 for in the instrument in which the action of the free electricity causes 

 increased divergence, the actual movement of the gold leaves will be =3, 

 for 1 + 2 = 3; and in the instrument in which this action tends to cause 

 diminished divergence, this tendency will be overpowered by the increased 

 divergence due to the reaction of the charge of electricity in the electro- 

 scope, and the actual movement which results will be one of increased 

 divergence =1 ; for the movement of increased divergence arising from 

 the reaction of the charge in the electroscope, = 2, minus the movement 

 of diminished divergence, = 1 , arising from the action of the free electricity, 

 must be increased divergence =1, for 2 — '1 = 1. 



In the account of these experiments, also, certain abbreviations are 

 made use of : thus i. d. stands for increased divergence of the gold leaves, 

 d. d. for diminished divergence of those leaves. 



For the rest, I have only to add that these experiments, which I leave 

 to tell their own story, with the aid only of a few short comments at the 

 end of each series, supply the first electroscopic indications of electricity in 

 living blood and in living nerve-tissue, and that, to say the least, they 

 clear up all uncertainty as to the presence in the living human body and 

 in living muscular tissue of electricity capable of supplying like indications. 



First Series. — Experiments which furnish electroscopic indications of 

 electricity in the living human body. 



In the first four of these experiments all that was done was to apply the 

 palm of my hand or the tips of my fingers to the cap of each electroscope 



