40 DROPS OF WATER. 



scientific Prussian, has fully ascertained that it 

 consists simply and wholly of the siliceous cover- 

 ings of certain minute creatures, some of which 

 belonged to species still to be found in stagnant 

 water. To common perception, the powder of 

 which the rock may be said to consist resembles 

 flour ; and in Norway, where it is called Berg- 

 mehl (that is, mountain meal), it is actually used 

 in times of famine as food ; for which it is not 

 entirely unsuitable, seeing that there is always a 

 per-centage of animal matter left in it, in addi- 

 tion to the siliceous shields.* So extremely 

 small are the creatures of which these rocks 

 form the sepulchre, that, according to M. Ehren- 



* Dr. Carpenter says, this earth contains a large proportion of animal 

 matter, about 80 per cent, of its weight. 



