52 EFFF.CT8 or POTASSIUM ON IROX. 



the sn-bstonoes addefl in the refining he suifaWe; but the 

 iron becomes redshort, if they he employed in too lar^e 

 proportion, whence it follows, that lime and potash are ca- 

 pable of rei. deling iron brittle. 



Does it render The opinion of some scientific men, \v]io presume that 

 the action of potash must render iron brittle; and the ex- 

 p(rin-»eiit in the large way at Zinsvviiler, which would induce 

 a belief, that potash occasions it to be redshort; would lead 

 metallurgists to ascertain by dliCc tand positive experiments 

 the influence of potash in its combiiuition with iron. 



the author Being at this moment engaged by order of his excellency 



wntinp; on the , ■ ■ ^ c ^i i ^ ^ i. • •^- .i 



artofTroti ^''^' minister of the home department in wntmg on the art 



ibuacUnjj. of treating and preparing iron, it was natural for me to at- 



tend to this question. Accordingly I requested the two re- 

 spectable chemists, to whom we are indebted for the disco- 

 very of the reduction of potash by means of iron, to favour 

 me with one of the gunbarrcls, in which they had repeated 

 their experiments a great number of times at the Polytech- 

 A gnrlarrel uic Sciiool. They had the goodness to choose me one, the 

 re-^e, t'edl'^'^^" inside of wh.ich was interiorly tilled with polassated iron, and 

 iwe<l for re- which the combination of potasl) had rendered so fusible, 

 ducmg jiou-h, ^i^^j. 1^ {j^j |j^ pj^^.^ melted during their experiments, 

 examined. The iron of this gun barrel, penetrated with potash, was 



assayed in presence of one of the pupils and myself by the 

 locksmith Rosa, who is commonly employed bj the Coun- 

 cil of Mines for the various trials of iron and steel. 

 Hested and The gunbarrel was heated and hammered flat for the 



flaiiened. length of four inclies on each side of the part fused by the 



combined action of the potash and heat. 

 Piere of alloy j,^ flattening it a portion of superpotassated iron was se- 

 parated, which we picked up. "^fhis little piece, weighing 

 lis prop;:itits. 4 gr. [0-2 grs.], was coldshort. In its fracture it exhibited a 

 mixture of a brown substance and a wj)ite. The latter had 

 the metallic lustre, and was pretty easily hammered when 

 separated from the brown substance. After 24 hours expo- 

 sure to the air the small piece was covered with moisture, 

 which it had attracted from the atmospheric air. 

 The barrel The barrel after being flattened and heated was forged 



wef.'i^d'^" aud welded very perfectly. It extended umlei llie hammer us 



bom Hiid casdv as coldshort iron. It was bent and twisted backward 



and forward several times, witliout the lea«tcrack appearing. 



A «mull 



twi-ted hot 



