664 SUMMARY OF CURRENT RESEARCHES, 



parities ; it was finally made by melting pure iron with phosphorus in an 

 atmosphere of nitrogen, in a carbon resistance furnace. A tantalum- 

 wire resistance furnace was also used. Up to 1*7 p.c, phosphorus forms 

 a solid solution with iron. This solid solution forms a eutectic with 

 Fe 3 P, melting-point a little over 1000° C, and about 10 ■ 2 p.c. phosphorus. 

 Fe 3 P forms a eutectic with Fe 2 P, 16*2 p.c. phosphorus, melting-point 

 960° C. Another eutectic appears to exist, and melts about 1218° 0. 

 The micro-sections were heat-tinted. 



