Professor Leslie on Electrical Theories . 
bursts by a discharge, and the violence is the greater the nearer 
the ends of the wires are to each other. 
Small bits of wood, charcoal, nitre, spars, and other minerals, 
are shivered or burst by a discharge ; but they are never perfo- 
rated. A small cylinder of clay, with wires inserted at the ends, 
is bilged by the shock into a globular form. When the discharge 
■4s made through a card, the part immediately under the knob is 
the most intensely electrified, and die difference of the proximate 
repulsion the greatest, and, the cohesion being small, an entire 
separation takes place ; at the same time, the lateral: particles 
are distended. Hence the small hole with a bur on each side, 
which is constantly observed. For the same reason, if a small 
phial be filled with oil, and a wire immersed in it, and the point 
brought near the side, the glass will be perforated by a spark. 
The same appearance is observed in spontaneous discharges. 
We may likewise see the reason why the sound of a discharge 
through the slow conducting fluids of the body is low and flat. 
Hence also the sensation of the shock, which is owing partly to 
the general distension of the particles, and partly to the greater 
difference of the repulsions between the fluids and the contigu- 
ous solids, Wherefore the shock is more violent when given 
to a single person than to a number joined in a circle ; for the 
gradation of intensity is more marked in the former case. When 
the communication is made through the head, the difference of 
the repulsions is greatest at the membranes which envelope the 
brain ; that delicate organ is compressed, and the stun is vio- 
lent. Hence, if the action lasts for a considerable time, an im- 
mense distension will take place. In death by thunder, the 
bones are dislocated, the vessels burst, and the body turned 
black by the extravasation of the blood ; the hat is rent, the 
shoes torn from the feet, and perhaps the heel, which is a slow 
conductor, is perforated. Hence also, the rocks are shivered ; 
the trees are split, or the bark peeled from the trunk. 
All these effects depend on the duration of the action ; and 
the great object is therefore to diminish that time. A broad, 
thick metallic substance ought to form the principal communi- 
cation between the thunder cloud and the ground. The best 
mode perhaps would be to continue the lead down from the roof 
