Bibliography. 211 



and sometimes it seems to exist in a very peculiar, colorless, and chem- 

 ically inexplicable state. This mechanical union of iron and silica ap- 

 pears to be chiefly an organic deposition of the metal in closed silice- 

 ous cells. 



" 10. In consequence of the uniform and extensive development of 

 minute organic life, it must exert a great and important influence upon 

 other conditions of the surface of the earth, and particularly upon the 

 formation of humus in the valleys of rivers. If the larger organic 

 bodies have direct relations to the conditions of the atmosphere, the 

 widely extended and immensely developed minuter forms, cannot be 

 without a great influence on those relations. 



" 11. But the evidence of the influence of microscopic life is not 

 confined to the surface of the earth. The same incomprehensible for- 

 mation of rocks from the siliceous or calcareous shells of animalcules 

 which is seen in the chalk formation of Europe, occurs also on a gi- 

 gantic scale both in the northeast and north vi^est of Africa, (Egypt, 

 Oran.) It occurs in the northwest of Asia, (Bir Hamam, Ante Liba- 

 nus, Libanus,) and according to recent observations in perhaps still 

 greater development in North America, (Mississippi, Missouri, New 

 Jersey.) The Jura limestones of Europe also show generally, and 

 sometimes quite distinctly, an intimate connection with organic life, 

 and the very ancient limestones and included chalcedony said to occur 

 directly beneath the coal at Lakes Tula and Onega in Russia, occasion- 

 ally show quite distinctly that microscopic life had as extensive a de- 

 velopment in that ancient epoch as at any more recent period. Rocky 

 masses of infusoria are presented by the polishing slates of Lucon and 

 Caucasus, and extensive earthy beds of siliceous infusoria occur, not 

 only in the edible clay of the Amazon, and the very extensive (fifteen 

 to twenty feet thick) infusorial strata of Richmond, Virginia, mentioned 

 by Rogers and Bailey, but also in the siliceous marl (Kieselguhr) in 

 Siberia, and near Perth in New Holland. 



" 12. Finally, microscopic life is demonstrated to be a most impor- 

 tant agent in the formation of the surface of the earth." 



J. W. B. 



12. Experimental Researches, Chemical and Agricultural, showing 

 Carbon to be a compound body, made by plants and decomposed by pu- 

 trefaction ; by Robert Rigg, F. R. S. London, Smith, Elder & Co., 

 65 Cornhill, 1844. 12mo, pp. 264. — This is a startling title, and our 

 conservatism at once takes the alarm ; for it threatens to subvert the en- 

 tire foundations of chemical science, and more especially those of phys- 

 iological chemistry, which seemed to be just emerging out of its chaotic 

 state into order and harmony. However, it claims to be only an experi- 



