Pine, white, for mechanical wood pulp, 108 ― wood fibre, 61 Pineapple fibre, 44, 46 Pink colours, 141 Pinus fibre, 60 Plant fibres, constitution, 1 ―, structural elements, 1 ― tissues mainly cellulose, 4 Pochin’s aluminous cake, 140 Poplar, composition, 61 ― fibre, 60 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 Pulp, beating, 117 ―, bleaching, 110 ―, ― refractory, 114 ―, colour of, produced by bisulphite, 77 ―, dimensions of fibre in, 119 ―, dry, preparing, 119 ―, duration of beating, 119 ―, freeing from bleach, 114 ―, improving colour, 114 ―, mixing, 119 ―, removing calcium hypochlorite from, 114, 127 ― saver, 114, 155 ― yield from straw, 99 ― ― ― woods, 77 Purification of water, 211 Rags, bleaching, 115 ―, boiled, draining, 84 ―, ―, washing, 85 ―, boiling, 82 ―, ― with lime, 83 ―, cutting, 81 ―, dusting, 82 ―, potchers, 89 ―, proportion of alkali, 83 ―, quantity of water for boiling, 84 ―, sorting, 80 ―, statistics, 221, 222 ―, time of boiling, 84 ―, treatment for paper, 79 ―, ― in washer, 89 ―, willowing, 81 Ramie fibres, dimensions, 39, 50 Raw material for paper, 1 Reagents for examining fibres, 36 Recovered soda, analysing, 205 ― ―, carbonising, 186 ― ― causticising, 187 ― ―, composition, 186 Refractory pulps, bleaching, 114 Repped paper, 171 Resinate of alumina, 137 Retree, 175 Rhea fibre, 50 Roeckner’s esparto boiler, 93 ― evaporator, 181 ― strainer, 150 ― water clarifier, 211 Rosin, 137 ― soap, 137 Rotary boilers unsuited to esparto, 90 Rubbing test for paper, 197 Rye straw, 98 Salle, 175 Salmon’s guillotine, 174 Save-all, 154 Schultze’s method of isolating cellulose from wood, 21 Schurmann’s calender rolls, 171 Schweizer’s reagent, 5 Sections of fibres for examination, 38 Seed hairs, 46 ― ―, dimensions, 39 Self-cleaning strainer, 149 Settling ponds, 125 Seventy per cent. white caustic, 178 Sheave, causes of, 90 Silk fibre, 31 Sinclair’s esparto boiler, 94 Single cylinder machines, 164 ― sheet cutter, 173 Siphon washer for boiled rags, 87 Site for mill, 210 Sixty per cent. white caustic, 177 Size, estimating amount of, 204 ―, ― nature of, 203 ―, making with gelatine, 162 Sizes of sheets, 175 Sizing, 137 Slicer, 151 Smalts, 141 Smell consumer, 183 Smoothers, 158 Smoothness, 159 Soaking wood, 107 Soap, analysing, 208 ― and gelatine, 163 ― for paper-makers, 163 Soda, action on cellulose compared with bisulphite, 76 ― ash, analysing, 205