652 



SERPENTINE. 



THE examination of a considerable tract of 

 this rock in Shetland, has, like the investigation 

 of the diallage rock of the same country, given 

 rise to an important correction of its history as it 

 was described in the body of the work ; and for 

 the same reasons it is introduced into the present 

 Appendix. 



There can be no doubt respecting- its stratifi- 

 cation in the island of Unst. Although less 

 regularly disposed in Fetlar, it seems there also 

 subject to the same law. It will be necessary 

 therefore to remove it from the division of the 

 unstratified rocks, and to place it with the pri- 

 mary strata, among which it may conveniently 

 follow limestone. 



In general, in the tracts above mentioned, the 

 great mass of serpentine seems rather to hold a 

 parallel course to the stratified rocks which it 



