PERFECT a.
which is perfectly coalescent and agreeable to the ear, as the unison, octave, fifth, and fourth; a perfect consonance; a common chord in its original position of keynote, third, fifth, and octave. -- Perfect number (Arith.), a number equal to the sum of all its divisors; as, 28, whose aliquot parts, or divisors, are…
PHASE RULE n.
, the system is invariant, that is, there is only one set of conditions under which these four phases can exist in equilibrium. If only three phases be considered, the system is univariant, that is, the fixing of one condition, as temperature, determines the others.