On alloying Iron with Manganese. 171 



Observations npon a mivufe Examination of the Remits of the 

 nine foregoing Experiments, relating to Fracture and mag- 

 netic Attraction. 



No. 1. In which no manganese was used, possessed the frac- 

 ture of No. ). Pig iron, soft and capable of being easily filed and 

 fully obedient to the magnet. 



Nos. 2 and 3. As relates to fracture, were fully more carbo- 

 nated than the former; and though 100 grains of manganese 

 had been fused in the mixture, the quality of the iron was soft 

 and easily filed. No diminution of magnetic force was percep- 

 tible. 



No. 4. The fracture of this latter was materially different from 

 the three former. The grain or crystal was smaller, the colour 

 lighter, and considerably harder under the file ; tb.e globules were 

 attracted by the magnet, but they approached with less force, 

 and perceptibly indicated a diminution of tliis action. 



No. 5. The present fracture as to grain was similar to the 

 last, with the exception of two distinct white lines running pa- 

 rallel with the under surface of the metallic button. Magnetic 

 force considerably diminished!. 



No. 6. The fracture of this result was regularly mottled en a 

 white ground; the file had little or no impression; a magnet of 

 the power of 20 pounds did not lift a globule of ISO grains. 



No. 7. Fracture similar to No. 6, with the exception of an 

 edging of gray minutely crystallized : the smallest globules were 

 not in the least acted upon. 



No. 8 and 9. Presented white silvery fractures, and so ex- 

 tremelv brittle as to pound readily in an iron mortar, which in- 

 dicates a quality very different from white fractured cast-iron. 

 No part of the metallic results of these experiments vvas in the 

 least acted upon by the magnet. One striking anomaly ap- 

 peared throughout : The alloyed buttons after the addition of 

 the ore of manganese presented surfiices covered with the most 

 shining carburet of iron common at iron-foundries; and this ef- 

 fect seemed rather to increase as the quantity of manganese was 

 enlarged and the carbonation of the fracture decreased, — a cir- 

 cumstance totally unknown in the fusion of simple ores of iron. 



Dear sir, yours truly, 

 ColefortI, Jan. IG, 1817. " " DaVIdMuSHET. 



P. S. Your last number contained an interesting account of a 

 mass of native iron found in South America, which I suppose is 

 the same alluded to in chemical and mineralogical books within 

 the last twenty years. On reading the account, I was pecuHirly 

 struck with its resemblance to those masses of iron sometimes 

 formed in the bottoms of our biast-furna::e3 in this country. 



Many 



