Scientific Intelligence- — Geology. 393 



it has risen six feot in 300 years, or at the regular rate of one foot 

 in fifty years. — Leonard's Jahrhuch for 1850. 



2. Rocks are not formed by hifusoria. — It is evident that infuso- 

 rial animalculcc can make their appearance, develope, and multiply, 

 only in those places whore they find an abundance of the necessary 

 nourishment in a form adapted to assimilation. Several species, 

 and these very widely difTused Infusoria, are distinguished from other 

 species by possessing certain inorganic constituents, namely, silica, 

 which forms the shells, or cuirasses, as they may bo termed, of 

 Naviculce, Exilaria, Bacillariay &c., and peroxide of iron, which is 

 a constituent of many Gallionellce. The carbonate of lime of the 

 chalk animalcula} is precisely similar to the shells of the common 

 molluscous animals. 



Many persons have pleased themselves with ascribing the enor- 

 mous depositions of silica, of lime, and of peroxide of iron in the 

 silicious fossil strata, in tripoli, in chalk, and in bog-ores, to the 

 vital process of primeval Infusoria ; as if the formation of these 

 enormous geological strata could be effected solely by the vital prin- 

 ciple ! But they have altogether overlooked the circumstance that 

 chalk, silica, and peroxide of iron, must first be present, as the ne- 

 cessary conditions of the life of these creatures, before they could bo 

 developed ; and that those constituents at the present moment are 

 never absent from the sea, the lakes, the marshes, where the same 

 forms of animalcula3 occur in a living state. 



The water in which these primeval Infusoria lived contained the 

 silica and the chalk in solution, and in a condition perfectly suitable 

 for their deposition in the form of marble, quartz, and other similar 

 mineral masses; and this deposition would have taken place in- 

 evitably in the ordinary manner, if the water had not contained the 

 putrifying and decaying remains of preceding races of animals, and 

 in them the other conditions of the life of silicious and calcareous 

 Infusoria. 



Without a combination of these circumstances — the presence of 

 these substances constituting the conditions of their existence — 

 none of these species of animalcula) would have propagated and in- 

 creased to form these enormous masses. These infusorial animal- 

 culsc can only be considered accidental media of the form which the 

 minute particles of these depositions exhibit ; — accidental, inasmuch 

 as even without these creatures, depositions of the silica, the lime, 

 the peroxide of iron, would have taken place. Sea-water contains 

 the lime of the coral animals, of the innumerable mollusks existing 

 in this medium, in the same form and condition as it is contained in 

 lakes, and in marshes, in which the chalk animalcula) developo 

 themselves, or those mollusks, the shells of which constitute the 

 muschelkalk formations. — Vide Dr Gregory^ s excellent edition of 

 Licbifs celebrated Letters on Chemistry, 3d edition, p. 243. 



3. On the Black Earth {Tchornoi Zem) of Central Russia. By 



