21. YORKSHIRE. 335 



of air, eighty-fix and a h:ilf grains of diflb- 

 luble matter, and thirteen and a half grains 

 of refiduuni, fine impalpable filr. 



The lime produced from the former is of 

 a dufky colour, and falls in rough coaifc 

 granules; that of the latter burfts into a white 

 volatile flour-like powder. 



The ftones of dificrcnt quarries are dif- 

 ferent in quality, but none of them differ 

 widely from the fpecimens above defcribed*. 



On the SOUTHERN HEIGHTS the prevailincr 

 material is a lingular fpecics of soft gra- 

 NATE. Its colour a dirty white : its con- 

 texture refembling the grains of white 

 muftard-feed run together with a cement of 

 chalk or marl. The hardncfs of this jtone 

 (if it merit the name) increafes with the 

 depth of the quarry. The lower blocks are 

 ufcd in building ; but the upper flratum, for 

 three or four feet below the foil, is generally 

 a STON'E-xMARL of no mcan quality, but varies 

 in different quarries. I have not learnt, how- 

 ever, that in any inilance it has been applied 

 as a MAN'URL. On the contrary, it appears to 



be 



* For a defcri;'tion of the ^iUAERiSs ofthefe ftrnes, 

 i";;e Alt. BuiLUi NG 3Ia'j£: RIALS, psge 105, note. 



