200 On the Fujion of Malhahle Iron 



cepllble. The quantity of revived lead amounted to g-? 



part the original weight of the flint glafs*. Grains; 



Bxp. XVII. Biitifli cold-lhoil iron - - 875 



Window glafs - 875 grains. 

 From this mixture, in half an hour, was obtained a 

 fine fufioii accompanied by an elegantly cryllallized 

 metallic button weighing - - - 835 



Loft in fufion, equal to —^ th part^, 39 



The frai^ure of this button was compofed of irregular cubes 

 inferted in each other. A bar forged from the half of this 

 button was loofe, and cracked in the edges. Its quality was 

 much akin to Kxp. XVI. Grams. 



jE.v/. XVIII. Bvitifli cold-fliort iron - - ^co 



Window glafs - 15^0 grains. 

 The button obtained from a fufion of the mixture 

 weighed . _ _ - 453 



Loft in fufion, equal to — ^ih. part, 47 



The quality of the metal now obtained was equally incapable 

 of being forged as that in Exp. IX and X. 



From the nature of the refults of thefe experiments it can- 

 not be fatis'^aiSlorily concluded bat even the fufion of Brilifh 

 cold-fhort iron with glaffes i& uniformly productive of the 

 fame quality of metal. But it may be fairly deduced that it 

 invariably is produftive of a crft malleable iron, harder and 

 much lefs ducMilc in every particular than the refuUs from 

 Swedifli iron fimilarly treated. 



The moft probable caufe of this irregularity of quality in 

 the cold-fhort iron I conceive to be cryftallization. In the 

 bar, this quality of iron always ■•refents cubes more or lefs 

 diftinft. When fufed, and allowed to cool under the cir- 

 cumftances necelTary to produce this effeft, a large pevfeftly 

 cryftallized frafturc is the confequence. This does not in- 

 variably happen ; but in two experiments out of three, I have- 

 found It to be the cafe. In a button of 10 to 1200 grains, 

 thefe cubes a.e found meafuring a full quarter of an inch 

 upon the facet; and fuch fometimes has oecn the degree of 

 divifion of the fluid, and a confequent perfciSt cryftalliza- 



'■* In this paper I have repeatedly ftated the fa£t of oxide of lead being 

 revived when no carbonaceous matter (that in the iron excepted) was 

 prefent. I fttall pafs over any inference to be made from this circumllanct, 

 until a fubjeft more immediately conjiefted with this curious fail is brought 

 forward in its proper place. 



tion. 



