March 1907.] 148 Fibres. 



process has 'so many features of superiority over the alkaline one that tits appli- 

 cation in the treatment of various other materials will be considered in a subsequent 

 paper when work on the value of Philippine woods for paper stock will be 

 reviewed.* 



Bleaching of paper pulp.— All fibres do not act alike with bleaching agents. 

 Jute, for example, does not bleach white by any known method which does not also 

 seriously injure the fibre while other substances require varying proportions of 

 bleach liquor and special conditions of treatment to secure satisfactory results. 

 Therefore, it is important to subject new, raw materials to quantitative bleach 

 operations in order to determine the right method of procedure and the amount of 

 bleaching powder required. The loading, sizing and coloring, of paper are not 

 materially affected by the source from which the pulp is derived and need only 

 concern us here with respects to the kinds of chemicals in general use for these 

 purposes and the possibilities of obtaining them in the local market. This question 

 of chemicals for this and the other steps in the process of pulp manufacture is an 

 important one and will be throughly discussed in a later number of this journal. 



Vegetable Fibres. 



Botanical classification. — Fibre-producing plants are included in two great 

 divisions of the vegetable kingdom— i. e., Dicotyledons and Monocotyledons. The 

 most evident characteristic of these two great divisions of plants is found in the 

 arrangement of the leaf veins. Dicotyledonous plants are characterized by netted- 

 veined leaves, whereas the monocotyeldonous ones may usually be identified 

 by leaves with parallel veins. The chief fibre-yielding families of the first 

 division are : 



Linacece : Flax family ; example, flax. 



Malvcece ; example, cotton. 



Tiliacece ; example, jute. 



Urticacea? or nettle family ; example, hemp, 



Moracew, example, midberry. 



Of the second division the Qraminem or Grass family, Liliacece, Palmce or 

 Palm family, and Musacece or Plantain family are the more important orders of 

 fibre producers. While a number of netted-veined fibrous plants such as ramie and 

 jute are distinctly tropical in habitat, only a few unimportant species are found in 

 the Philippines aud hence it appears that families of Monocotyledons are the only 

 ones represented by plants of commercial importance in these islands. 



Structural classification.— -With the exception of fibres like cotton, kapok 

 etc., which are unicellular seed hairs and termed surface fibres, practically all fibres 

 may structurally be classified according to the two main groups of families from 

 which they are derived. The dicotyledonous plants produce the so-called bast fibres, 

 contained in the inner fibrous bark of stems and twigs, while on the other hand the 

 commercial fibres of monocotyledonous plants are generally found distributed 

 throughout the entire stem, where they form the frame work which gives rigidity 

 and toughness to the plant structure, and hence they are termed structural fibres. 

 Such fibres occur in the sheathing leafstalks of plantains, in the fleshy leaves of 

 maguey and pineapple, and in the leaves and stalks of palms and grasses. 



* " On account cf the considerable proportion of silica present in straw.it has generally been 

 assumed that this material would not easily lend itself to treatment by the sulphite process. Practical 

 experience has, however, shown that this is not the case, and this process has recently been applied to 

 the preparation of straw pulp with excellent results." Griffin & Little : Chem. of Paper Making 161 



