262 



Scientific Proceedings, Royal Dublin Society. 



It. D. S., vol. iv., 1884, p. 311, and need not be here re-given. 



At the present time only this clay is worked for the manufacture 



of alum, although the associated lithomarge and bole are very 



similar in aspect to the ferriferous varieties of the French and 



Grerman clays {beauxyte and tvoeheinyte) . It would, therefore, 



appear expedient that the bole and lithomarge should be more 



minutely tested, especially the light-coloured varieties of the 

 latter. 



The mining in the alum- clay {alumyte) is quite of recent date. 

 Its value was first discovered by Mr. Walter Jemerson in 1873, 

 who began to work it in 1874 : since then the trade has largely 

 developed. 



The following are analyses of the alumyte, beauxyte, and 

 woeheinyte, procured through Mr. Jemerson : — 



The analysis of the alumyte was made by John Pattison, 

 Nawcastle-on-Tyne. In the French and German analyses the 

 alumina is both hydrated and anhydrous. As sulphuric acid, in 

 the process of alum making, only extracts the hydrated alumina ; 



