PHASE RULE n.
o systems of chemical equilibrium, discovered by Prof. J. Willard Gibbs. It may be stated thus: The degree of variableness (number of degrees of freedom) of a system is equal to the number of components minus the number of phases, plus two. Thus, if the components be salt and water, and the phases salt, ice, saturated…
PIPEFISH n.
Any lophobranch fish of the genus Siphostoma, or Syngnathus, and allied genera, having a long and very slender angular body, covered with bony plates. The mouth is small, at the end of a long, tubular snout. The male has a pouch on his belly, in which the incubation of the eggs takes place.
PIPIT n.
Any one of numerous species of small singing birds belonging to Anthus and allied genera, of the family Motacillidæ. They strongly resemble the true larks in habits, colors, and the great length of the hind claw. They are, therefore, often called titlarks, and pipit larks.