92 The Microscope. 



CHAPTER IX. 



ORGANIC REMAINS, CRYSTALS, AND ARTIFICIAL OBJECTS. 



]HE microscope affords a great deal of informa- 

 tion to the geological inquirer, not only with 

 regard to the real nature of various animal 

 and vegetable remains which are found as fossils in 

 the different strata, but also with regard to the com- 

 position of the strata themselves. 



Fossil trees have been found in various strata, more 

 or less perfect. Sometimes their fibres have been 

 completely penetrated by the mineral " silica," some- 

 times by carbonate of lime, and when this has occurred, 

 their minute cells and vessels are well preserved, and 

 it is quite possible to make thin sections of them 

 capable of being compared with those of recent wood. 

 There are certain markings of cells and fibres by 

 which the wood of a cone-bearing tree (larch, for 

 instance,) may be readily distinguished from such 

 trees as the oak and elm. Other characteristics mark 

 the palm tribe, and all these structures may be 

 observed in the fossil woods of the newer strata. In 

 the earlier strata, the cone-bearing trees and the 

 palms are, with rare exceptions, the only forms dis- 

 covered; and in coal, which the microscope has 



