x8o On the Affiiy'mg of Iron Ofcs 



worthy of the ilniplc elements of fcicnee. The following 

 one in particular feenis lo polTcfs an air of incongruity even 

 in the proportions, only equalled by the oddity of the aHem- 

 blap'C of mixtures brouahl forward; 



*' lOO Grains of the roaltcd ore, two parts of the black 

 '' flux, (equal parts of borax and nitre,) one part of tartar, 

 " one of fal-amnioniac, one of fandever, half of (again) 

 *' borax, half of glafs, one-fourth of clean foot, one-fourth 

 *' of charcoal; the whole to be covered with common fait." 

 This motley aflbciation of earths, alkalies, and falts, is re- 

 commended as the beft flux for all iron ores. The author 

 however fliews, that the advantages which it poflcfles are not 

 complete, from the great caution prefcribed in the mode of 

 conveying the neceffary degree of heat ; and the perfeftion 

 of the operation is rendered altogether doubtful by theconfe- 

 quences which the overfight oiafew minutes may occafion. 



It cannot be well reconciled to our ideas of advancement 

 in any art, that we have not yet difcovcrcd a method of ope- 

 ration more perfeft than that wherein a few minutes loft or 

 gained (which error will more likely take place from the in- 

 equality of heat, than the reckoning of time,) make a varia- 

 tion from truth equal to i-^th or i-6th of the whole. The 

 nianufafturer would be in a lamentable predicament were 

 he thus circumftanced, and obliged, by fome means or other, 

 to take the crude iron from the blaft-furnace inuncdiately 

 upon being feparated from the ores, left a confiderable por- 

 tion of it fliould totally difappear. If the degree of heat pro- 

 duced from a fmith's forge was at all times the fame, though 

 fupplied with fuel of various natures, and under different 

 changes of temperature, then it i? moR probable that, by 

 reckoning Bergman's time to a minute, a button of iron, 

 accurate in its rcfults, might be obtained from 'fame ores by 

 the flux he has direAed to be ufed. But I cannot conceive 

 that this fliould be an univerfal confcquence : far lefs can I 

 comprehend, after a juft fcparation has been cfic6ted, that 

 9 five 



