GIBB — A CHAPTER ON FOSSIL LIGHTNING. 
195 
A CHAPTER ON FOSSIL LIGHTNING. 
By G. D. GiBB, M.D., M.A., F.G.S., Member of the Canadian Institute. 
The expression " fossil lightning" may seem somewhat paradoxical, 
but it is here employed in a figurative sense to designate a condition 
of things which we have good modern evidence to prove to have been 
the result of the lightning's flash, myriads of ages gone by. Of late 
years vitrified sand-tubes have been discovered in Cumberland, in 
Prussia, South America, Natal, and other places ; and these have been 
very clearly made out as having been directly caused by lightning, 
and hence they have been called by mineralogists " Fulmiuary tubes" 
or Fulgurites. All these would appear, so far as we can ascertain, to 
have been formed at comparatively a very recent period, and hardly, 
therefore, deserving of the appellation of "fossil lightning." Never- 
theless, as I have come across some examples of such bodies on the 
surface of the flagstones which form our pavements, and of the an- 
tiquity of which there cannot be any doubt whatever, I have no 
hesitation in making use of the term which heads this chapter. 
If I had at one time any scruples upon this point, they were re- 
moved whilst attending the instructive lectures so eloquently delivered 
by that great philosopher and distinguished comparative anatomist, 
Professor Owen, at the Museum of Practical Geology, in the early 
part of the last year. He used this expression, in his first lecture on 
Fossil Birds, when particularly speaking of the various modes in which 
the evidences of evanescent things become recognisably preserved 
in rock, as illustrated by meteoric phenomena, footprints, soft and 
soluble plants, and animals. The " fossil lightning," as exhibited in 
the British Museum, he lucidly described, and pronounced some of it 
even to be forked. As further illustrating evanescence, I may for the 
moment refer to some specimens of rain-prints and shrinkage-cracks 
on the under side of layers of carboniferous sandstone from Cape 
Breton (Nova Scotia), figured and described by Sir Charles Lyell, in 
the Geological Society's Journal and in his " Manual of Geology." 
The large size of the rain-drops would indicate most probably a vio- 
