A poisonous nonmetallic element of the nitrogen group,
   obtained as a white, or yellowish, translucent waxy substance, having a
   characteristic disagreeable smell. It is very active chemically, must
   be preserved under water, and unites with oxygen even at ordinary
   temperatures, giving a faint glow, -- whence its name. It always occurs
   compined, usually in phosphates, as in the mineral apatite, in bones,
   etc. It is used in the composition on the tips of friction matches, and
   for many other purposes. The molecule contains four atoms. Symbol P.
   Atomic weight 31.0.