334 FRAGMENTS OF SCIENCE. 
death, this would occur without pain. Death in this case 
would be simply the sudden negation of life, without any 
intervention of consciousness whatever. 
The time required for a rifle bullet to pass clean through 
a man's head may be roughly estimated at a thousandth of 
a second. Here, therefore, we should have no room for 
sensation, and death would be painless. But there are 
other actions which far transcend in rapidity that of the 
rifle bullet. A flash of lightning cleaves a cloud, appear- 
ing and disappearing in less than a hundred thousandth of 
a second, and the velocity of electricity is such as would 
carry it in a single second over a distance almost equal to 
that which separates the earth and moon. It is well known 
that a luminous impression once made upon the retina 
endures for about one-sixth of a second, and that this 
is the reason why we see a continuous band of light when 
a glowing coal is caused to pass rapidly through the air. 
A body illuminated by an instantaneous flash continues to 
be seen for the sixth of a second after the flash has become 
extinct; and if the body thus illuminated be in motion, it 
appears at rest at the place where the flash falls upon it. 
When a color-top with differently colored sectors is caused 
to spin rapidly the colors blend together. Such a top, 
rotating in a dark room and illuminated by an electric 
spark, appears motionless, each distinct color being clearly 
seen. Professor Dove has found that a flash of lightning 
produces the same effect. During a thunderstorm he put 
a color-top in exceedingly rapid motion, and found that 
every flash revealed the top as a motionless object with its 
colors distinct. If illuminated solely by a flash of lightning, 
the motion of all bodies on the earth's surface would, as 
Dove has remarked, appear suspended. A cannon ball, 
for example, would have its flight apparently arrested, 
and would seem to hang motionless in space as long as the 
luminous impression which revealed the ball remained upon 
the eye. 
If, then, a rifle bullet move with sufficient rapidity to 
destroy life without the interposition of sensation, much 
more is a flash of lightning competent to produce this 
effect. Accordingly, we have well-authenticated cases of 
people being struck senseless by lightning who, on recov- 
ery, had no memory of pain. The following circumstan- 
tial case is described by Hemmer; 
