320 ANNUAL OF SCIENTIFIC DISCOVERT. 



Fossil infusoria have been detected in great numbers. They 

 were first discovered in certain silicious deposits, near Berlin, I)ut 

 have been since recognized in all parts of the world. The silieious 

 and ini])erishaljle envelop, before alluded to, cnal)le3 them to be 

 minutely investigated. These shell-like integuments, visible only 

 under the microscope, constitute masses of white powder, known 

 as mountain meal {herfj meld, German \ farinc de montagne, French). 

 In Swedish Lai)land, under a bed of decayed moss, is found an 

 immense stratum of this substance. These fossil infusoria do not 

 of themselves constitute an aliment of suflieieut nutriment to sus- 

 tain life ; but in China, where " mountain meal " al)ounds in some 

 districts, it is made use of to mix witli other food. Infusorial earth ■ 

 has been founil in America at West Point, and in dilferent locali- 

 ties in New England. Some of the deposits are fifteen feet in 

 thickness. Richmond, Virginia, reposes on a bed composed 

 almost entirely of such earth. 



Tlie city of Berlin is built upon such a deposit, consisting of 

 microscopic animals and plants, some of whicii are still living and 

 I)ropagatt! daily with great rajjidity. Their existence is doubtless 

 maintaiiifd l)y the waters of tin; Spree, situated on a higher level, 

 and which liltcr through the deposit. It is feared that a period 

 will arrive when a portion of the town will fall in, on account of 

 tiie rapid development of these creatures, some of which, accord- 

 ing to Ehrenl>erg, form in the space of fom' days no less than 

 two cubic feet of new movable earth. 



The polished slate of Bilin in Prussia, which js used for polish- 

 ing mi'tals, glass, marble, etc., is entirely composed of the sili- 

 eious shells of infusoria and otiier animalcula, and forms a stratum 

 fourteen feet thick. One cubic inch of this polished earth has 

 been shown by accurate measurement and calculation, to contain 

 fort\--oue millions individuals of gallionella distans, and 1,750,000,- 

 000 of galliondla ferruginea. 



The material chalk appears to owe its origin in great part to 

 remains of myriads of animalcula, principally ybra?«t/ii/era. They 

 secrete a calcareous shell or covering, similar to that of the sili- 

 eious infusoria. 



The calcareous bed of the tertiary formation, known as num- 

 mulite limestone, is an interesting study, on account of the enor- 

 mous quantity of nummulite shells — larger foraminifera — which 

 it contains. This limestone can be traced from the Pyrenees, 

 through the Alps and Apennines, into Asia Minor, and further, 

 through northern Africa and Egypt, into Ai'aljia, Persia, and 

 northern India. A similar deposit occurs in the Paris tertiary 

 basin, and in that of Brussels. The fine-grained and easily 

 worked limestone, which affords such an excellent material for 

 the decorated buildings of the French capital, is almost entirely 

 formed of accumulated masses of the minute shells of foramin- 

 iferous animalcula. In this nummulile limestone, the matrix in 

 which the nummulites are imbedded, is itself composed of the 

 more minute foraminifera, and of the broken and cemented frag- 

 ments of the larger pieces. — Druggists' Circular. 1866. 



