| Compounds containing manganese and phosphorus were prepared at the end of the eighteenth and beginning of the nineteerth century using the methods described by Pelletier, Percy, Rose, Schrotter and Wohler (loc. cit.). The freezing-point-composition diagram of the two elements shows a eutectic at 964° C. (first additions of phosphorus), a maximum freezing-point at 1390° C. corresponding to Mn3P2 another eutectic at 1095° C., and another maximum at 1990° C. corresponding to MnP. Alloys containing between 10 and 20 per cent, of phosphorus are magnetic. The monophosphide MnP was a black powder which was fairly easily oxidised by heating in the air. |