On the AJfay'ing of Ores ly Fujion. 385 



of iron ores ; that part of the water — by far the greateft — . 

 which remained undecompofed, would ferve as a medium, or 

 vehicle of fufpenlion, and conveyance to the oxvde; this 

 again, in its turn, would be depofited either at the fountain- 

 head, or at a greater or leffer diflance from it, according to 

 the affinities exerted upon it by other fubftances with which 

 it might come in contacl. Corrtfponding with this fuppo- 

 fition, we commonly find thofe ores which are formed in 

 vertical maffes or knobs, approached by a great number of 

 fmall veins occupying the fmalleft fiifure or crevice in the 

 rock. Time, and the re-action of additional water and 

 acids, would a fecond time carry ofl' a portion of the ore iii 

 chemical union ; this, by the exertion of new affinities, 

 woidd become precipitated, and mixed with the fufpcnded 

 earths, to forni regular ftrata of iron-ftone. To fuch a pri- 

 mary and fccondary agency of formation may be attributed 

 the general fuperior richnefs of ores found in irregular ver- 

 tical malTes, to that of iron-ftones. The fame caufe will 

 alfo explain why more determinate qualities of iron are ob- 

 tained from primitive ores, than from thofe of a fecondarv 

 formation. In the former, the mixtures are commonly 

 fewer, and the quality of the malleable iron more decided j 

 in the latter, the quality of the metal is lefs certain, and morcr 

 various, from the mixtures being more numerous. Hence 

 we may alio trace the reafon of the fuperior qualities and 

 marks poirelTcd by fome of the foreign fabrics over each 

 other, where the fame fuel has been ufed, and tlie fame courfc 

 of manufafture followed. 



Having fo far conlidered crude iron, in regard to its fufi- 

 bility, and the facility with which it becomes changed into 

 various degrees of carbonation or oxvgenation, conlUtutiug 

 a variety of qualities moil pointedly diiiinguiHied in com- 

 merce, and in which tlic metallurgift difeovcrs widely dif- 

 ferent propertie** and chara6lerifl;ic forms; I fhall next pro- 

 ceed to mention in what manner ftrcntrth mav be <riven to 

 any quality of crude iron which may probabiv be obt lined 



bv 



