ig4 The Newly ’Discovered Force. [April, 
The spark of this force resembles the scintillating spark 
of dynamic electricity, so also do sparks produced by 
combustion. The velocity of this force is great, but so is 
that of light. This force is best conducted by metals, but 
so also is heat. 
This force is resisted by non-conduCtors, but heat is simi- 
larly resisted, and both to a less degree than electricity. If 
it be as I have suggested, a form of electricity which is so 
rapidly reversed as to be practically depolarised, it would 
yet be electricity under very different conditions from those 
under which we are wont to consider it, and would be really 
a new force. The more I experiment in this department, 
and the more closely I reflect on the results of experiments, 
the farther I seem to be driven from the eleCtrical toward 
the radiant theory of this force : in either case there would 
appear to be no ready escape from the acceptance of the 
conclusion that we have here something radically different 
from what has before been observed by science. 
The relation of this force to the other forces may be thus 
represented : — 
Light, Heat, . . New Force, Electricity, Magnetism. 
The above would represent Mr. Edison’s theory of a 
radiant force, nearer to light and heat than to electricity or 
magnetism. 
The theory I have suggested would ally the force to 
electricity or magnetism more than to light and heat, as 
follows 
Light, Heat, ....... New Force, Electricity, Magnetism, 
Presumption against the Validity of the Claim. 
But it is yet too early to accept either theory. Although 
in the abstract there is no reason why a new force, or seve- 
ral new forces, might not exist in nature, the phenomena of 
which should be revealed by chance or otherwise, and which 
are now unknown and unsuspected, because we have no way 
of knowing the conditions necessary to produce them ; yet 
practically, and in the concrete, the presumption against the 
validity of any claim to the discovery of a new force is in the 
first instance enormous, and can only be overcome by an 
enormous amount of expert evidence. Science it is said is 
sceptical ; it ought to be sceptical. The sources of error in 
studying phenomena believed to be new are so numerous 
that the statements of the first experimenters cannot be 
