8i6 
Proceedings of Societies . 
[December, 
each other so as to form a spiral cord, round which the blood 
capillaries also wind. Dr. Shettle compares these nerve and 
muscle bundles to the coils of zinc and copper wire in his expe- 
riments, and infers that eleCtric currents may be induced in them 
as in the wires. The flow of the warm magnetic blood would 
also tend to produce currents in them. Dr. Shettle, further, 
drew attention to the faCt that animals live and move in a mag- 
netic field, and that electricity must be generated in them by 
their movements, internal and external. 
Mr. Emmott exhibited Crossley’s Form of Microphone, which 
consists of four short rods of carbon jointed loosely into four 
blocks of carbon, so as to form a square. It is used as a trans- 
mitter for telephones, and Mr. Crossley regularly transmits the 
services of a church with it to several hearers. Its speaking, 
singing, and whistling powers were successfully demonstrated to 
the meeting. 
Royal Society, Nov . 20. — Dr. Spottiswoode, President, in 
the chair. 
“ Experimental Researches on the EleCtric Discharge with 
the Chloride of Silver Battery,” by Warren De La Rue, M.A., 
D.C.L., F.R.S., and Hugo W. Muller, Ph.D., F.R.S., Part III. 
In the first part of this paper the authors describe a series of 
experiments to determine the potential necessary to produce a 
discharge in a tube, exhausted gradually more and more while 
using a constant number of cells in all the experiments. The 
tube employed was 33 inches long and 2 inches in diameter, 
the distance between the ring and straight wire terminals being 
2975 inches; the battery consisted of 11,000 cells. The next 
part of the paper deals with the potential necessary to produce a 
discharge between discs 1-5 inch in diameter, at a constant dis- 
tance and at various pressures ; the remainder being chiefly 
occupied with the study of the phenomena of the eleCtric arc 
under various conditions of distance, pressure, and potential. 
The experiments were made in a bell-jar, containing the ter- 
minals, which could be gradually exhausted after having been 
filled with air or other gas. A remarkable phenomenon was 
observed on making connection between the terminals and the 
battery by means of the discharging key, namely, that within 
certain limits of pressure in the bell-jar a sudden expansion of 
the gas took place, and that as soon as the connection was 
broken the gas then as suddenly returned nearly, but not quite, 
to its original volume in consequence of a slight increase of tem- 
perature. The effeCt was exactly like that which would have 
been produced if an empty bladder had been suspended between 
the terminals, and suddenly inflated and as suddenly emptied. 
This is thought to be produced by a projection of the molecules 
by electrification causing them to press outwards against the 
walls of the containing vessel, this pressure being distinCt from 
