48 Experiments made on a Sample of Pig Iron 



By this treatment there were obtained 2*48 per cent, of 

 bright, metallic, non-magnetic particles, and 7'43 per cent, of 

 slightly magnetic, metallic particles. 



Upon analysis one hundred parts of the non-magnetic 

 particles contained : — 



Percentage of iron ... ... ... ... 85*44 



„ chromium ... ... ... 14*95 



carbon trace 



10039 



Upon boiling a portion of these particles in nitric acid, 

 they were converted into the silvery plates. 



One hundred parts of the slightly-magnetic particles gave, 

 upon analysis : — 



Percentage of iron 87*55 



„ chromium ... ... ... 11*28 



silica and undetermined ... 1*17* 



10000 



A number of these slightly magnetic particles were boiled 

 in a flask with nitric acid (1 part of nitric acid with 2 parts 

 of distilled water) until the solution ceased to be coloured 

 by the dissolved iron. Those silvery white particles as 

 mentioned under the "Nitric Acid Treatment," were obtained. 



Upon analysis these plates gave in 100 parts : — 



Percentage of iron ... ... ... ... 84*44 



chromium ... ... ... 15*56 



100*00 



This shows that a large percentage of those non-magnetic 

 silvery plates are left in the magnetic mass, even after very 

 careful treatment with the magnet ; this no doubt is owing 

 to the plates being impregnated with the surrounding 

 particles of metallic iron. 



The quantity of star-like forms in the hydrochloric and 

 residue did not suffice for an exact analysis, but their be- 

 haviour with acids shows that they differ in composition 

 from the silvery plates. 



One sample of the iron gave minute prismatic needles in 

 place of plates, upon treatment with nitrohydrochloric acid. 



These examinations show that the assumption that the 

 chromium is alloyed or combined with the whole mass of 



