196 TROWBRIDGE. — IIIGiI ELECTROMOTIVE FORCE. 
electrician knows that no inductive effect between one storage cell of much hio-he 
voltage than that of any nerve or muscle can be detected, even when the velocity of 
the electrical action in the inducing cell is many times that of the nerve action. To 
the electrician the supposed electrical condition of human muscles and nerves resem- 
bles that of a number of suburban towns, each with individual electrical plants not 
connected to any central station ; and the physiologist who can show any ramifica- 
tions which are analogous to those by means of which electrical energy is transmitted 
by inorganic machines would overcome much scepticism among physicists in regard 
to the real existence of electrical currents in human muscles and nerve. 
There is, however, one. analogy between the action of a storage cell and that 
of a nerve. This analogy can be found in the phenomenon of electrical diffu- 
sion. We recognize this diffusion in the ordinary voltaic cell, which is so universally 
used in ringing call bells and door bells. These cells discharge, so to speak, their 
■gy with a resultant fatigue, and, afte 
pable of exhib 
energy again. The electrical fish, it is said, recuperates after giving a shock. This 
recovery of a cell source of electricity is shown on a comparatively great scale by a 
large storage battery. This phenomenon is painfully apparent to the automobilist 
who drives an electric automobile ; for it is an evidence of fatigue in his battery, and 
it gives an elusive hope of recovery. Have we not seen such an automobilist sud- 
denly coming to a stop, and rest a moment, until by the phenomenon of diffusion in 
the battery the electromotive force rises sufficiently for him to proceed ? An elu- 
sive hope, I have said, for another period of fatigue will soon set in, and the periods 
of necessary rest become longer and longer. In the rise and fall of electromotive 
force, due to diffusion, we have something very analogous to the recuperation and 
fatigue of nervous energy ; and it is through the study of this phenomenon, I 
beheve, that we shall gain some insight into the mysteries of what is called animal 
icity 
The large storage battery of the Jefferson Physical Laboratory exhibits the peri- 
ods nse and fall of electrical energy in a manner most suggestive to one who thinks of 
the analog.es between such a collection of units of electrical energy and the supposed 
collection of similar 
fish. When the battery is suitably 
nected to a reservoir like a Leydcn jar, this reservoir rises to a defi..... «~..„~„ 
force and then discharges by means of a spark. The curve of rise and fall remi 
one of the curves obtained by physiologists, denoting action and fati.ue in the e 
ditions of muscles 
thnt tWo r i i The dischar S es of th e battery can be so closely regulated 
that these discharges can be made as regular as the beatin, of the human he^t. If 
