Porion’s evaporator, [182]
Porter-Clark process for water, [214]
Potchers, felting caused in, [113]
— for bleaching pulp in, [111]
— for rags, [80]
Presse-pâte system for esparto, [96]
— — — for straw, [101]
Pressure for boiling straw, [100]
— in relation to soda, [64]
Prussian blue, [142]