THE 



LONDON AND EDINBURGH 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[THIRD SERIES.] 



MAY 1837. 



LXIII. Cyanide of Potassium^ an incidental Pi oduct of the 

 Process for making Cast Iron in Blast Furnaces. By Thomas 

 Clark, M.D., Professor of Chemistry in Marischal Col" 

 lege and University, Aberdeen,'* 

 TOURING the last three years, a salt, which, when melted, 

 ■*-^ is clear and colourless, but which, when solid, is of an 

 opake white, and generally not cr3'stalline, has been observed 

 to exude in the liquid state, from cracks, and other accidental 

 outlets, around the tweers of the hot-blast furnaces for making 

 cast-iron, in the Clyde iron-works. The salt occurs in greater 

 quantity at one time than at another ; but I have not yet been 

 able to ascertain the circumstance in the process upon which 

 the supply of the salt depends. The workmen say, that it 

 occurs most after what they call a scour of the furnace, that 

 is, after, by an excess of the fluxing ingredients of the smelting 

 process, or an increase of the fuel, the materials acci- 

 dentally adhering to the inner sides of the furnace have been 

 dissolved away. The salt in question, however, may exude, 

 under such circumstances, not because it is produced in greater 

 quantity, but merely because it then finds a readier outlet at 

 the tweer, where alone it has hitherto been observed. At 

 the Clyde iron-works, the salt has occasionally accumulated in 

 such quantity as to require a wheelbarrow for its removal. 

 Upon minute inquiry I found that a similar product, although 

 it had attracted no attention, occurred at other iron-works in 

 Scotland, wherein, as at the Clyde iron-works, the hot blast and 



* Communicated by the Author. 



Third Series, Vol. 10. No. 62. May 1837. 2 U 



