On the A(fdying of Ores hy Fiifion. 381 



it apparently ridiculous, merely bccaufe it is at variance vvitk 

 out prejudices. Where Icicnce guides not the mamifafturer, 

 or IS Iconied bv hnii, his train of realoning, though far from 

 being jufl, is lliort ; it is fitted to tlw: narrow culture of his 

 mind, and confonant to a barbarous nomenclature of re- 

 ceived ufage *. 



In arder to elucidate ftill farther how much the quality of 

 the iron is dependent upon the proportions of the mixtures, 

 in combination with, or given to the ores, let a determinate 

 quantity, fay an ounce, of the oxyde of pure malleable iroa 

 be taken; — this we arc phyfically certain contains no mixture 

 except oxygen exi(ting in quantity proportioned to the ilage 

 of oxydation, the quantity being afcertained by its degree of 

 obedience to the magnet; when the quantity of oxygen given 



• I cannot rcfift noticing one inftance, prevalent at iron-works, of that 

 blind reverence to the -opinion of our predcccffors, \vh»fe fourccs of know- 

 ledge muft nect-iTarilv have Ijeen few and cotitrafted. When fupcr-car- 

 tonatcd crude iron is run from the furnare, it is frequently covered witli 

 a fcurf, which \^'hen cold is found to be a c\);iting of plumbag© (caphviret 

 «f iion) remarkably brilliatit; fometiir.es in fm.ill fpecks, and :at other 

 times in large flakes: this fubllance is univerfally denominated //i'/j&^ot-, 

 and, as the moll exprcHive adjective for that qviality, we fiv that ilie iron 

 is fulphury. Tliere are not, perhaps, two iubftar.ccs fo oppoiite in thew 

 degrees of inflammability, or fo widely ditferent in their properties, as 

 fulphur and plumbago; the exiftence of the latter ahnoll wlvoiiy fuppofo 

 a total abfence of the former : yet, fuch is the want of invtftigation, or tlte 

 fliglitcU monientary rtfleftion, thaT an indolent belief is pafled as to the 

 prelcncc of a I'ubltance dianieu-icaily oppofite to that which is cxpreffed. 

 .i'.v//'i;<r has hitherto been tlic philolbpher's ftoiie of the iron manufajitoryj 

 t" its prcfence is attributed the produclion of bnd iron — when the metal is 

 in its moft valuable llatc, it it ^^o ful^<'oury \ — it prevents caft iron irorn 

 becoming malleable; xnnil'xi ft<!l<hur were altogether abfent, hardorw'hkc 

 caft iron could not be produced. If c?.ft iron is found coloured, it is by 

 i\\e ful^bur ; is it cryliallifcd and coloured, then it has fulphur to eitcefi; 

 fliould it have loft its (Irength, or have become loofe in the fraflure by aa 

 excefi of Ihriftlcagc in larjje caftingo, ftill it is by the ag<:ncy of fuJphors 

 in fliort, in every procefs in the manufaduring of iron, fulphur eKplaiiw 

 the whole phenomena ! it is execrated in one procefs, wid anxioufly looked 

 for in another. 



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