Siliceous Earth found near Oherohe. 377 



termining several species of infusoria, whose coverings form this 

 silica, and in ascertaining that there occurs, in the lower bed, a 

 species of infusoria found in the polishing slate of Habichtswald 

 and Hungary ; and another peculiar to the Kieselguhr of Bo- 

 hemia; both of which seem to be entirely wanting in the 

 upper bed : but upon these points we shall defer further re- 

 marks, in order that we may not anticipate the pubHcation of 

 the completed investigation of Professor Elirenberg. 



That a mass more than twenty feet in thickness should 

 consist almost entirely of the coverings of animals which are 

 invisible to the naked eye, and which can only be recognised 

 with the assistance of a high magnifying power, is an extraor- 

 dinary fact, and one which the mind cannot fully comprehend 

 without some difficulty. The farther we attempt to pursue the 

 subject the more we are astonished. That which occurs in an 

 invisible condition in the fluid element, and which cannot be 

 recognised by the human senses without the assistance of art, 

 becomes, by immense accumulation and solidification, one of 

 the circle of phenomena which are witnessed by us in the ordi- 

 nary way ; a compact mass is formed, which can be weighed, 

 felt, and seen ; and this mass is presented to us in such quan- 

 tity, that, when regarded only in one direction, it surpasses 

 by three times the height of the human figure. Who could 

 venture to calculate the number of infusory animals which 

 would be required to produce even one cubic inch of this mass ? 

 And who could venture to determine the number of centuries 

 during which the accumulation of a bed of twenty feet in thick- 

 ness was taking place ? And yet this mass is only the product 

 of yesterday compared with the other more compact siliceous 

 masses for which the infusoria of a destroyed creation affbrded 

 materials. But what would have become of that loose, light 

 silica, — which, by its great porosity and its power of absorbing 

 water in quantity, in some measure indicates its origin, — if, in- 

 stead of being covered by soil one foot and a half in thickness, 

 it had been covered by a great mass of earth or rock ; or if an- 

 other power, such as the action of fire, had caused its solidifi- 

 cation ? In that case, we should have had no bed twenty feet 

 in thickness, but should perhaps have found a compact stony 

 mass, capable of scratching glass, affording sparks with steel, 



