J. Trowbridge—Electro-motive action of Liquids. 345 
the electrical currents supposed to be circulating in the arms, 
By the contraction of one arm the muscular current becomes 
enfeebled, and the current of the other arm predominates. It 
occurred to me that experiments with the U tube might throw 
of the human fingers, a vessel aaa 
(fig. 2) with two limbs, which were 
connected with each other at the = aby = 
top. ta b are pieces of = oro ES 
flexible tubing, and the extremi- a {4 Sra Em 
tes ¢ and d were covered with F =f =e: 
prepared membrane; A was = ee 
ed with a weak solution of ——ed—Et---Et—ia 
t. 
The resistance of the circuit was nearly that of the human 
body from the forefinger of one hand to that of the next, and 
equal to seven or eight times that of the Atlantic cable. The 
extremities of the tube were then immersed in the liquid of the 
connecting vessels, the same precautions being observed as 
are advised by DuBois Reymond. Upon the first contact with 
the liquid, the spot of light from the galvanometer was deflect- 
ed over 200 divisions of the scale, and upon the reversal of the 
limbs the direction of the deflection was also changed. By 
pinching the flexible tube of one of the limbs, this deflection 
could be greatly lessened. 
currents claimed by the electro-physiologists ; and the further 
culty of conceiving how muscular contraction can effect 
this current, lead me to believe that the deflection of the needle 
resulting from the contraction of the muscle of the arms 18 
produced either by the perspiration or by the change in the 
flow of the blood.” It may be mentioned in this connection 
that the electromotive force between arterial and venous blood 
18 2.43, if we represent that of a Daniell’s cell by 76-42. 
(Scoutetten, Experiences nouvelles pour constater lelectricite 
