THE PA GE OF NA TURE. 1 75 



through the old red sandstone, with its numerous strange 

 and monstrous fishes ; the carboniferous strata, with 

 their countless forms of gigantic vegetable life ; and 

 the limestone rocks, the graves of whole hecatombs of 

 madrepora, through all these different geological de- 

 posits we can trace the presence of these little plants. 

 Endowed with the power of investing themselves, as if 

 by a mysterious process of electrotype, with the silicious 

 matter held in solution by the waters in which they 

 abound, they are in truth indestructible ; and of their 

 remains, individually so minute that thousands may be 

 contained in a drop, and millions packed together in a 

 cubic inch, deep beds of marl, extensive chains of hills, 

 huge limestone rocks, ay, even whole territories of allu- 

 vial soil, have been in a great measure composed. 



In Virginia, there are vast beds of silicious marl, com- 

 posed of the skeletons of countless generations of diatoms; 

 and it is said that the towns of Richmond and Peters- 

 burg, in the same province, are built upon an enormous 

 stratum of these plants, every cubic foot of which con- 

 tains billions more than the living population of men 

 that throng the streets above them. Extensive tracts 

 covered with similar relics of a former age occur through- 

 out Britain ; the peat mosses of Ireland and the High- 

 lands of Scotland abound with them, and hundreds of 

 species have been found beautifully preserved in the vast 

 amber beds of Prussia. The peculiar white powdery sub- 

 stance known by the name of Berg meld, or mountain 

 meal, found in Swedish Lapland, under beds of decayed 

 moss, and mixed by the inhabitants with their food 

 in times of scarcity, is composed of fossil diatomacea?, 



