70 LIVING LIGHTS. 



man to turn up the earth, when the scene that followed is 

 described as truly magnificent. The soil appeared as if it 

 had been sprinkled with molten gold, the display being 

 intensified if the insects were trodden upon or rubbed ; in 

 the latter case, streaks of light appeared, as if a bit of phos- 

 phorus had been placed upon the hands, the light being 

 distinctly visible for twenty seconds. 



The Geophilus electricus (Plate XIII., Fig. 2) is a small, 

 inconspicuous insect, about an inch and a half in length, and 

 one tenth of an inch in diameter. Like others of its kind, 

 it lives in holes in the ground, and, when discovered, makes 

 off rapidly by the use of its one hundred and forty legs. 

 The interesting fact that the luminous secretion could be 

 separated from the insect was originally noticed by Macart- 

 ney seventy years ago, who found that the fluid, as he terms 

 it, could be communicated by the centipede to every portion 

 of its integument. This author also claims that the insect 

 is only luminous after exposure to the sun, a peculiarity 

 that is found in certain minerals described in a later chapter. 

 The most remarkable exhibition of the luminosity of these 

 insects has been recorded by Mr. B. E. Brodhurst, who saw 

 it first twenty paces away, so vivid was its display. The 

 light looked like moonlight, so bright was it through the 

 trees. " It was a dark night, warm and sultry. Taking a 

 letter, I could read it. It resembled an electric light, and 

 proceeded from two centipedes and their trails. The light 

 illuminated the entire body of the animal, and seemed to 

 increase its diameter three times. It flashed along both sides 

 of the creature in sections, there being about six from head 

 to tail between which the light played. The light behaved 

 precisely like the electric light ; moving, as it were, perpetu- 



