^ 



46 



ILLUSTRATIONS OF THE 



and laftly, that if 

 fuch tubes, it wo 

 they did not all c 

 one another. 



ftone was perforated by 



Id flillbeinfi 



'^adlj join, or inofculate 



that 



rt 



9. The compenetration 



d 



f 



heterog 



fiirnifned a proof of 

 hy fire. 



Th 



it may be call- 

 inces, has here 

 having been melted 



fabil 



fi 



f 



one 



S 



fubllance within another, as happens among the 

 fpars and drufens, found fo commonly in mine- 



ral veins, often leads to a limil 



fi 



^ 



Dr Hutton has 

 d fatisfad:ory proof, 



Thus, from a fpecimen of chalcedony, including 



in it a piece of calcareous 



derived a very ingenious a 



that thefe two fubilances were perfedly foft m 



the fame time, and mutually affeded each othei' 



the moment of their concretion *. 



Each of thefe fubilances has its peculiar fo 



to itfelf, it naturally aflum 



a 



\ 



th 



ft 



taking the form of rhomb 



c cryftals, 



and the chalcedony affefting a mammalated ftruc- 

 ture, or a fuperficies compofed of fpherical kg- 

 ments, contiguous to one another. Now, in the 

 fpecimen under confideration, the fpar is inclu- 

 ded in the chalcedony, and the peculiar figure 

 of each is impreifed on the other; the angles and 

 planes of the fpar are indented into the chalce- 



dony, 



I 



* Theory of the Earth, vol. i. p. 93 



