40 



so incorporated with it, that it is not to be discerned where 

 they end or where the Carbonate of Lime begins. Thejila- 

 •ments run perpendicularly to the more dense or cork-like 

 surface of the upper and lower sides of the specimen, which 

 however has more of a cottony texture, but is much finer 

 than any cotton or vegetable thread: the first seems infinitely 

 fine; the latter may be seen by a microscope to show a 

 finally confirmed hollow filament*. It generally is found 

 in Serpentine rocks. 



* I was highly pleased to find in Mr. Carlisle's Croonian lecture read to 

 the Royal Society, Nov. 8, 1804, that he had determined the final filament 

 in muscular flesh. I had been much puzzled with the assertion that Lewen- 

 hoeck had found them infinitely divisible : having long since taken the pains 

 to examine a piece of mutton flesh, I found the smallest filaments easily 

 discernible, and according with Mr. Carlisle's accurate account, as far as 

 I examined, but they are not so in Asbestus, or any filamentous earth. 



