Chalk and Flint Formation. 33 



occurred in the days of Joshua — " He shot out his 

 arrows and scattered them, — hailstones and coals of 

 fire." These arrowy ellipsoids, coming down not 

 always in perfectly parallel lines, seem occasionally 

 to have impinged on one another and cohered to- 

 gether in a slightly angular manner. Of this I pre- 

 sent a specimen. And in one instance I have found 

 a specimen which distinctly tells its own tale of its 

 meteoric source and descent ; for it consists of one 

 of these arrowy ellipsoids of flint, which has come 

 down upon two thin layers of tabular flint, both of 

 which had been at the time not perfectly hardened, 

 the upper one softer, the other more tough. Through 

 the upper of these two tabular pieces the descending 

 arrowy flint has quite penetrated, and dinted out 

 the lower, but has been partly forced up again 

 by the toughness and elasticity of the lower, and 

 has drawn up along with it the edges of the upper 

 where it had penetrated. It has had a longitudinal 

 slice cut off at the same time, apparently by lightning. 



I have carefully used the microscope for the 

 testing of my conclusions in minute particulars ; 

 but the main facts which are rested on are patent to 

 the naked eye, and are too manifest to need, or to be 

 affected by, any process of examination by thin 

 slices microscopically scrutinized on Dr. Bowerbank's 

 method. The microscope, however, renders very 

 distinct the white grains of chalk disseminated in 

 the dark flint, and confirms the general absence of 

 the woody fibre in the interior of specimens from 

 the Petrified Forest of Cairo, as well as in that of 

 the flint specimens of tree-roots. In the former, 

 indeed, it is not quite so absolutely so, the fiery 

 " rain" 3 having been probably in a more perfectly 



3 Exod. ix. 34, ")DD (comp. Gen. xix. 24, l^DJl). Fire, and 



D 



