Definition. - A mixture of solid hydrocarbons, chiefly of the methane series. The paraffin of the U.S. Pharmacopoeia melts between 51. 6 and 57.2 C. (I24.9-I35 F.). The "hard paraffin" (paraffinum durum) of the British Pharmacopoeia melts between 54.40 and 57.20 C. (129.9-135 F.), while the "paraffinum solidum" of the German Pharmacopoeia melts between 740 and 8o C. (165.2-176 F.).