666 REPORT — 1894. 



specimens the veins are seen to be planes along which the sandstone is cemented 

 by barytes. The specific gravity of the rock is 3'09, and, as the grains are chiefly 

 subangular fragments of quartz and felspar, it must contain about 28 per cent, 

 of barytes. This almost insoluble cement has undoubtedly given rise to the spur 

 above alluded to, and almost as certainly has caused the survival of the Peakstones 

 Rock, which now, however, is so much exposed to the weather on all sides, and both 

 to mechanical and chemical disintegration, that if any cement is still left it can only 

 be in the inner part of the mass which cannot be reached by ordinary means. Another 

 specimen from * West of Kent Green, near Congrleton,' containing barytes, and with 

 a structure very like that described by Mr. Strahan, was also referred to. The 

 paper was illustrated by a set of photographs which the author owed to the kind- 

 ness of Mr. A. A. Armstrong and Mr. P. Simpson. 



12. Report of the Committee on the Volcanic Phenomena of Vesuvius. 



See Reports, p. 315. 



