[April, 
ig2 The Newly-Discovered Force. 
of tin-foil connected with the other end of the divided wire, 
through which the force was conducted to the dark box. In 
this way I proved that the force could pass through inches 
dry wood, two plates of glass each 5- of an inch in thickness, 
J of an inch of hard rubber, J of an inch of solid paraffin, 
and 5 layers of paraffin paper. When the surfaces at the 
end of the wire were reduced in size, or when the tin-foil at 
one end was removed, the force passed less easily. When 
the tin-foil at both ends was removed, and only a few inches 
of fine wire constituted the surface, the force passed through 
only thinner resistances, and when only the terminals of the 
wire were applied to the surface of the resisting body the 
force would not pass at all, or but a very slight distance. 
The force passed through 20 inches of water in a small 
tube, and was apparently but little diminished even when 
the surface at the terminals was but the diameter of a small 
wire. 
When a number of “ sounders ” are in action near to- 
gether, and connected with the same or different batteries, 
the force can be captured by a piece of wire a few inches 
long, connected with the dark box, and held at a distance 
of several inches from any of the sounders. This is, how- 
ever, no exception to the law that the force passes resistance 
by surfaces, for the sounders here constitute one surface 
and the few inches of wire the other, making a condenser or 
Leyden jar. 
Some of the early experiments with this force gave 
erroneous or unsatisfactory results, because it was not 
known or suspected that with surfaces at the terminals it 
would pass through bad conductors even when the apparatus 
was not insulated. 
In experimental researches we may learn oftentimes more 
from our blunders than from our successes. In studying the 
passage of this force through glass, the mistake was made 
of overlooking the conduCtibility of the air and the human 
body. On a long glass rod, held by a stand, were wound 
the terminals of the divided wire through which the force 
was passing. Before the rod stood one of the experimenters, 
placed his hands on the ends of the wires and pushed them 
an inch apart, and the spark appeared in the dark box. He 
pushed them several inches apart, still appeared the spark ; 
yet farther, the entire length of the glass rod, 2 feet or more, 
yet the spark — though fainter— -was easily seen. The in- 
ference, which for a number of days was unchallenged, was 
that the force passed through the long glass rod, though 
somewhat resisted by it. This inference was wrong. We 
