A HISTORY OF SCIENCE 



new structure has been assumed which is peculiar to 

 a certain state of the calcareous earth. This change 

 is produced by crystallization, in consequence of a pre- 

 vious state of fluidity, which has so disposed the con- 

 certing parts as to allow them to assume a regular 

 shape and structure proper to that substance. A body 

 whose external form has been modified by this proc- 

 ess is called a crystal; one whose internal arrangement 

 of parts is determined by it is said to be of a sparry 

 structure, and this is known from its fracture. 



" There are, in all the regions of the earth, huge 

 masses of calcareous matter in that crystalline form or 

 sparry state in which, perhaps, no vestige can be 

 found of any organized body, nor any indication that 

 such calcareous matter has belonged to animals ; but 

 as in other masses this sparry structure or crystalline 

 state is evidently assumed by the marine calcareous 

 substances in operations which are natural to the 

 globe, and which are necessary to the consolidation of 

 the strata, it does not appear that the sparry masses 

 in which no figured body is formed have been orig- 

 inally different from other masses, which, being only 

 crystallized in part, and in part still retaining their 

 original form, have ample evidence of their marine 

 origin. 



" We are led, in this manner, to conclude that all the 

 strata of the earth, not only those consisting of such 

 calcareous masses, but others superincumbent upon 

 these, have had their origin at the bottom of the 

 sea. 



" The general amount of our reasoning is this, that 

 nine-tenths, perhaps, or ninety-nine-hundredths, of this 



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