270 
particle to another within that extent of the series which is 
already fully agitated. In other words, the communicated 
vibration does not attain a sensible amplitude, until a finite 
interval of time has elapsed from the moment when one 
should expect it to begin, judging only by the law of the 
propagation of phase through an indefinite series of particles, 
which are all in vibration already. A small disturbance, dis- 
tinct from the vibration (3)’, is also propagated, backward as 
well as forward, with a velocity = a, independent of the 
length of the wave. And all these propagations are accom- 
panied with a small degree of terminal diffusion, which, after 
avery long time, renders all the displacements insensible, if 
the number 2, however large, be finite, that is, if the vibra- 
tion be originally limited to any finite number of particles. 
Dr. Apjohn read a paper by George James Knox, Esq. 
“on the Direction and Mode of Propagation of the electric 
Force traversing Media which do not undergo Electrolyza- 
tion.” 
In the commencement of this paper, the author details 
experiments, which appear to him to justify the inference, 
that when an electric circuit is completed through water or 
melted phosphorus, the current passes directly through the 
substance of these media, but that when, for these, a metal 
such as lead is substituted, the electricity moves exclusively 
along its surface. He next considers the source and mode 
of propagation of the electric force, developed in the pile, 
and after a brief review of the theories and experiments of 
Davy, Faraday, and Becquerel, arrives at the following con- 
clusion, viz. that an electric current originates in a natural 
electro-inductive power of bodies when brought into contact, 
which affects the circumambient ether of each particle, and 
is coutinued by alternate states of induction and equilibrium ; 
the amplitude of the oscillations of the electrical ether con- 
