148 



Prof. Ehvenberg on Fossil Infusoria. 



XIV.— Selections. 



I.— Remarks on the real Occurrence of Fossil Infusoria, and their 

 €X:i.e7isive Diffusion; hij Pro/. Ehrenberg. 



From J. C. Poggendorff's Jlnnalcn dcr riiTjsik tind Chemie, vol. xxxviii. No. 5, 



p. 213*. 



[The following eloquent passage from the notice of Dr. Bugkland's 

 Geology in the April No, of the Fdinhtirgh Review,\vil\ have intimated, 

 in general terms, to many of our readers the astounding nature of M. 

 Ehrenberg's discoveries: — 



" Extraordinary as these phenomena Corganic remains) must appear, 

 the recent discoveries of Ehrenberg, made since the publication of Dr. 

 Buckland's work, are still more marvellous and instructive. This emi- 

 nent naturalist, whose discoveries respecting the existing infusorial ani- 

 mals we have already noticed, has discovered fossil animalcules, or 

 infusorial organic remains ; and not only has he discovered their exist- 

 ence by the microscope, but he has found that they form extensive strata 

 of tripolij or poleschiefer (polishing slate) at Franzenbadin Bohemia, — 

 a substance supposed to have been formed from sediments of fine 

 volcanic ashes in quiet waters. These animals belong to the genus 

 Baccillaria, and inhabit siliceous shells, the accumulation of which 

 form the strata of polishing slate. The size of a single individual of 

 these animalcules is about l-288th of a line, or the 3400th part of an 

 inch. In the polishing slate from Bilin, in which there seems no 

 extraneous matter, and no vacuities, a cubic line contains, in round 

 numbers, twenty-three riiillions of these animals, and a cubic inch 

 FORTY-ONE THOUSAND MILLIONS of them. The Weight of a cubic inch 

 of the tripoli which contains them is 270 grains. Hence there are 

 187 millions of these animacules in a single grain; or the siliceous 

 coat of one of these animals is the 18 millionth part of a grain ! 



" Since this strange discovery was made, M. Ehrenberg has detected 

 the same fossil animals in the semiopal, which is found along with the 

 polishing slate in the tertiary strata of Bilin, —in the chal/c Jiints, and 

 even in the semiopal or noble opal of the porphyritick rocks. What 

 a singular application does this fact exhibit of the remains of the 



* This paper was read in the Royal Academy of Sciences of Berlin on the 7th July, 

 1836. [The translation is by Mr. W, Fkancis,] 



