EFFECTS OP POTASSIUM ON IRON. • 51 



VI. 



Extract of a Letter on Potassated Iron from Mr. Hassen- 

 FRATZ, Kngineer in Chief of Mines, and Piofessor of 

 3Iinera!og>/ at the Practical School of Mines, to Mr. Gil- 

 LET-LAUMONfT, Correspondent of the Institute, and Mem- 

 ber of the Council of Mines*. 



A OU are acquainted with the beautiful experiments, in Aikalis de- 

 ^'hich Gay-Luss<ac aiv^ Thenard have decomposed potash l^^on^"^*^ ^ 

 and soda by means of iron, and obtained metals that com- 

 bine readily with iron, producing alloys, from which nitrate 

 of potash is obtained wlien they are treated with nitric acid. 

 You know too, that crude iron is pretty generally obtMined fif"^ smelted 

 in France by fusion with wood charcoal, which contains ^^' 

 more or less potash ; and that this is afterward refined with 

 the same combustible to produce -malleable iron ; whence it 

 is hij^hly probable, that the potash contained in the char^ 

 coal is reduced, and afterward combines with the iron in the 

 processes it undergoes. 



Oak charcoal yields about eight parts of saline matter in Proportions olf 

 a thousand, beech five, elm twenty, poplar six, fir two, &c. l^^^^^rcoaT 

 A mean of the charcoal commonly employed will produce 

 seven parts of salt to a thousand of fuel; and if 500 parts 

 of charcoal be used on a medium to 100 of iron, it follows, 

 that two or three per cent of the new metal may combine 

 with the iron formed. 



The small quantity of the new metal that can combine Iron injured 

 with iron in the different processes it undergoes might ,e- ^y ^'^'^'^ 



, . „ , „ ■ , quaiitiiiesof 



move the apprehensions of those metallurgists, who are in- alloy. 

 clined to ascribe injurious effects to it, that quantities as in- 

 considerable of phosphorus, sulphur, copper, &o., will ren- 

 der iron, the first coldshort, the other two redshort. 



From the small combinations of potassium and iron hith- Trials slould 

 erto made, it is difficult to form a judgment of the influ- be made on a 

 ence of this new metal on the goodness of iron, because the ^^^^ ^'^'^ '"* 

 quantities obtained were too small to be forged : but not- 

 withstanding the smallness of the buttons of JDotassatcd iron 

 that have been fused, some men of science have thought, 

 that the compound was brittle. When coldshort iron is an r^ these 

 purified at Zinswiller on the Lower Rhine with lime and *^''^"i to show, 

 potash, iron of good quality is obtained, if the quantity of potash ^i^mes 



* Journal des Mines, vol. XXll I, p 275. , '""""• 



£o the 



