﻿

6 2 



T H 



A 



R A 



T 





R 



becomes a kind and luxuriant foil : from hence we may learn both the nature and 



manures of clayey land, as well as the manner of fitting it for every purpofe. 



The following feem to be the moil compound fubftances of this nature, that I have 

 obferved in a folid form, in that Ifland, viz. 





CRYSTALLUS 



Conico-cylindracea uirinq, 

 The needle cryftal. 





r This fpecies is found in that freeftone near the bath : the cryftals are very fmall, and 

 hardly perceptible to the naked eye ; but when the workmen break any of the ft 



fragments that fly about 



fo charged 



.1 



thefe minute (harp-pointed 



yftals, that they inflame and frequently blifter the fkin wherever they touch 



Columnar is hexaedra, hinc tantum pyr ami data, later ibils 



CRYSTALLUS 



duobus tnajoribus oppofi, 

 The pointed cryftal with two oppofite fid 



than any of the reft. 

 3 . Columnaris hinc tantum obliqud pyr ami data. 

 The obliquely pointed cryftal. 



g 



There is but little difference between thefe two fpecies ; but the former feems 

 fhoot more freely, and to be lefs tranfparent in its appearance : they are both very 

 har v d, and mark glafs, or the beft poliihed fteel, with great ea 



i 







2. 



Subaqueum. 



The aqueous Quartz. 



SublaSteum. 



The white and fubopake Quartz. 



QUARTSZUM 











L 



3. Subrubellum diaphanum. 



The fubtranfparent Quartz, with a flefhy caft. 



4. Diaphanum albidum. 



The whitifh tranfparent Quartz. 



5. Nigrum arenaceum nit ens. 

 Black fand, or black Quartz. 



All thefe fpecies are frequent in Jamaica : the three firft are commonly found in 

 detached mafles, and feem to have much of the nature, and appearance of flint: the 

 fourth is the true parafitical native fort, and found frequently mixed with many of the 

 copper ores. The fifth is rather a fterii iron ore, than a Quartz ; but as it is generally 

 found of an angular comprefTed form, and eludes the action of both the fire, and the 

 acid, I have given it a place in this clafs ; it is very common in many parts of Ame- 

 rica, and moft frequently found in this form on the fea fide, but is fometimes ob- 

 ferved to be a principal mixture in many of the harder fpecies of grain ftones in this 

 part of the world. 



^ 





I 



: 



LYDIUM 



1 



f 1. Atrum equale. 



The Touch-ftone. 

 Cinereum equale. 



The Afti-coloured Lydium. 

 Duriffimum e jufco grifeum . 

 The Thunderbolt. 

 Atro fubceruleum . 

 The Indigo-coloured Lydium. 



Rubellumfubfibrofum. ' 



The brown Lydium with a fibrous texture. 



Ail 



















' 



