CAUSES OF PRESERVATION. 163 



of the osseous texture ; and we therefore see the bones of men and animals 

 preserved in the catacombs of Egypt, and the subterranean vaults of Koine, 

 Naples, and other places. 



Again, an immersion in water, to such a depth as to prevent the water. 

 contact of air, preserves, not only bones, but the trunks and roots of trees, 

 and even vegetables, from decomposition. It is well known that there is 

 a bridge across the Danube, at Augsburg, in Germany, the wooden piers of 

 which have lain under water for a number of centuries, and are still quite 

 sound. It is not uncommon to find the trunks and roots of trees in lacus- 

 trine deposits, in rivers, and even in the ocean, covered by layers of other 

 roots and other trees deposited long after them. 



Animal substances, protected by superincumbent earth from the action 

 of air, have been known to resist, for unknown ages, the tendency to decom- 

 position. 



The seeds of various plants, also, after having been buried in the earth 

 for a great number of years, at the distance of some feet from the surface, 

 have not only escaped decomposition, but have actually germinated when 

 placed in favorable circumstances. 



The great number of fossil bones found in the vicinity of the Salt Licks, salt Licks, 

 proves, as may be readily believed, that the earth of these districts, impreg- 

 nated with the chloride of sodium, has a greater power of preventing their 

 decomposition than the common soil of the country. Mr. Ansted, an excel- 

 lent writer on Geology and Palaeontology, has said, in a recent work ("The 

 Ancient World," p. 300), that " perfect skeletons of the Mastodon have been 

 obtained from the great salt marshes in North America." This is a mis- 

 take : no perfect skeleton of Mastodon has been found in the salt marshes 

 or Salt Licks of North America. Of the five skeletons known at this time, 



