244 JAMAICA, 



fome of the fulphvireous fprings In the ifland derive their qualities 

 from this fource. The varieties of the lead ore found here are the 

 fubgraiuilated, linked with filver; the lamellated, fhlning ore, in 

 the fame union ; the black-gloHy ore, linked with copper, and lefs 

 impregnated with filver; and the black, lead ore, largely admixed 

 with copper, and feldom rich ; but the matrix is mellow, and eafily 

 fluxed [;']. Stibium has been frequently found in thefe lead mines. 



Iron ore has been difcovered in many parts of this ifland ; but 

 the very large quantities of black fand, which are thrown on many 

 parts of the South fide coaft, efpecially near the mouths of rivers, 

 having been hurried down by floods, are much more acceffible, and 

 with little pains. This fand is obfervable almofl every where in 

 the roads and gullies after hard rains ; fo that the foil of the fa- 

 vannahs, as well as that of the mountains, is impregnated with it. 

 The inhabitants ufe it in common, like what is called in England 

 the black writing-fand. It is freely attradted by tlie magnet ; but 

 does not anfwer, it is faid [/], with the acid, or fire. However, it 

 mufl be referred to future experiment to difcover, whether it be 

 not endued with the fame properties as the Virginia black fand ; 

 particularly as, upon trial of the Virginia fand fome years ago (an 

 account of which is given in Lowthorp's Abridgement of the Phi- 

 lofophical Tranfadlions, vol, II.), aquafortis produced no ebullition, 

 and fluxing obtained no regulus, nor any fiibftance that would apply 

 to the magnet, except a thin cruft, that adhered to a piece of char- 

 coal, which dropped into the crucible during the fufion. For which 

 reafons, this fand was imagined to be very flightly engaged with 

 iron ore, and in fuch a manner, as that the metallic particles could 

 not be feparated and fixed by the ufual procefs. But Mr. Home, 

 fufpefting thefe experiments not to be decifive, conceived that the- 

 fand was not altogether and fimply iron; but that it was ftrongly 

 united with a very flubborn, fixed, and permanent earth, which 

 could not be feparated from it without fome extraordinary as well 

 as powerful! means. The Ingenious artift, proceeding upon this 

 fuppofition, fpread about eight or nine ounces of the fand, unmixed 

 with any addition, upon an iron plate, over a ftrong fire, and gave 

 it a very powetful torrefaftion, or roafting, to try if by that means 



[;■] Browne.. 



he 



