68 APHORISMS AND REFLECTIONS 



elsewhere, and had pointed out that, if it were 

 commercially worth while, rotten-stone might be 

 manufactured by a process of diatom-culture. Ob- 

 servations conducted at Cuxhaven, in 1839, had 

 revealed the existence, at the surface of the waters 

 of the Baltic, of living Diatoms and Radiolaria 

 of the same species as those which, in a fossil 

 state, constitute extensive rocks of tertiary age at 

 Caltanisetta, Zante, and Oran, on the shores of the 

 Mediterranean. 



Moreover, in the fresh-water rotten-stone beds 

 of Bilin, Ehrenberg had traced out the metamor- 

 phosis, effected apparently by the action of perco- 

 lating water, of the primitively loose and friable 

 deposit of organized particles, in which the silex 

 exists in the hydrated or soluble condition. The 

 silex, in fact, undergoes solution and slow redepo- 

 sition, until, in ultimate result, the excessively fine- 

 grained sand, each particle of which is a skeleton, 

 becomes converted into a dense opaline stone, with 

 only here and there an indication of an organism. 



From the consideration of these facts, Ehrenberg, 

 as early as the year 1839, had arrived at the con- 

 clusion that rocks, altogether similar to those which 

 constitute a large part of the crust of the earth, 

 must be forming, at the present day, at the bottom 

 of the sea ; and he threw out the suggestion that 

 even where no trace of organic structure is to be 

 found in the older rocks, it may have been lost by 

 metamorphosis. 



It is highly creditable to the ingenuity of our 

 ancestors that the peculiar property of fermented 

 liquids, in virtue of which they " make glad the 

 heart of man," seems to have been known in the 

 remotest periods of which we have any record. All 



