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A 



M 



A 



A. 



61 



Both theft 



of Mica are frequent in J, 



efpecially among thof< 



that lie between St. Katherines and Sixteen-7nile-%valk ; the laft fort has been f re 

 quently warned down with the floods, and fbmetimes taken for a lighter fpeci< 

 gold fand : it is commonly found incorporated with the potters clay near Spani/h- 



s o 



f 



i. 



Friabile, Jibris fubdiapanis hngitudinalibus. 



The Tricherium with longitudinal fubdiaphane fib 





TRICHERIUM 



2. Per Jlratas difpofitum, Jibris obliq 

 The Tricherium with fhort fibr 



in ftrata. 



3 . Nigrum fubnitens ferro imp 



difpofed obliquely 



The black Tricherium with glofiy flakes, and impre 



nated with 



- 



Thefe fubftances are frequently obferved in Jamaica, i 

 £ne cement ; but they have not been yet tried in that Idand 



d may probably yield 



AMIANTHUS 



f DuriJJimus externe granulatus i h 



\ The hard lamellated Amianthus 



lam el I at us 



it is 



They have great quantities of this fubftance both in Antigua, and Jamaica : 

 generally found in large detached mafles, having all the appearance of petrified Wood 

 for which it is commonly taken in both iilands. 



Purpurafcens quaquaverfum fijjilis fcriptura atra< 

 The purpleifh Schift with black lines, and fpliting 



freely in all directions. 

 Spato impregnatus & ftptis divifus. 



The mixt Schiftus. 



SCHISTUS 



■ 



The laft fpecies is frequently found in the furf about Bull-bay ; the acid attacks, 

 and diflblves the cement of the mafs with great fury ; and leaves an inert lump of 

 pure fchiftic earth behind . The other is common in many parts of the mountains of 

 St. Johns j but is generally fteril, and of little ufe. 



T. 



VI. 





Of Clay y and clayey Sub/lances. 



■ 



Argilla 





Subcinerea, fiffilis. 

 Refining clay. 

 Te/Tulata arena mixta. 

 Potters clay, or fandy clay. 

 Sabulo & terra mixta. 

 Clayey foyl. 



Thefe are the mod remarkable appearances of clay, in the vifcid ftate, now ob- 

 ferved in Jamaica. The firft is almoft pure, and very fit for the refinin^-houfe, as 

 well as for earthen wares, if they mould ever think it neceflary to work in fuch a ma- 

 nufacture, but it is not very common. The fecond fort is more frequent, and now 

 fupplies the Ifland with water-jarrs, and other conveniencies of the like nature. 



The third forms a great part of the foyl in many places j and is fufficiently re- 

 markable for its ftiffhefs, and cohefion : when it abounds with fand without earth, 

 it is the true brick-clay ; but, when any confiderable quantity of this is joined in the 

 mafs, it breaks its texture, and the clod is lefs cohefive; by which means it frequently 



. $ becomes 



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