344 AMERICAN FORESTRY 



supply, and not subject to violent fluctuations either in quality or price; (6) 

 it admits of simple and ready treatment, mechanical, chemical or both, for 

 easy and inexpensive conversion into bleached pulp; (7) land established in 

 bamboo, which will take three years from first planting to reach a height of 

 thirty to forty feet, can then be reaped annually for an indefinite period. 



Ordinary thick-walled bamboo, which, when given suitable soil and 

 clima+e, grows with amazing rapidity and yields annually at least forty tons 

 to the acre, contains fifty per cent of a very strong, yet fine and flexible, fibre, 

 easily digested by the ordinary bisulphite process, and by a new method 

 simply and inexpensively bleached, yielding when properly treated an excellent 

 pulp, felting readily, and producing a paper, pliant, resistant and opaque, of 

 enduring color, thicker than other paper of the same weight, and forming one 

 of the very finest of materials for writing and printing, and of exceptional 

 value for engraving. 



The oldest bamboo is thoroughly and completely digested, knots and all, 

 by the ordinary bisulphite process ; but care must be taken in the cooking, as 

 there is no reason to suppose that all bamboos are alike. Pine 

 spruce, and poplar are treated quite differently in cooking, and 

 nearly every factory has its own formula, and difierent strengths and tem- 

 peratures are used. Direct steam should never be used with bamboo, but 

 always steam coils with not more than forty pounds pressure until the last 

 two hours, after first liberating the gases derived from bamboo which are 

 different from those of wood. The mechanical portion which is absolutely 

 essential to this process is a preparation of the bamboo for cooking as well 

 as for bleaching. After being selected and assorted the bamboo has to be 

 crushed in exactly the same manner as sugar cane, when it will appear after 

 removal of the sap somewhat similar to mogass, almost pulverized and a 

 slightly damp, spongy mass. In this form the bamboo is extremely permeable 

 by the cooking solution, w^hich can be used comparatively weak and without 

 any necessity for a high pressure of steam. In all cases a solution to be used 

 with bamboo should be as nearly neutral as possible. It may be slightly 

 alkaline or slightly acid, but excess in either direction will waste a large 

 amount of the fine fibres, and acts adversely on the chemical constituents of 

 bamboo. These fine fibres are, according to Wildridge and Ekman, of great 

 value in forming a close, opaque sheet of paper. They represent about a third 

 of the cellulose, and unless the necessary precautions are adopted, they will 

 be lost in the strainers and washers. So, obviously no part of the preparatory 

 treatment can be carried out away from the place of growth of the bamboo. 



The bleaching process is entirely new and differs from any other used 

 for making pulps. It consists in an intermediate process the object of which 

 is to prepare the pulp for bleaching, by steeping the bamboo after it has been 

 cooked for a few hours in a solution made from electrolysed sea-water, salt, 

 and diluted sulphuric acid, then after drawing ofif the solution (which can 

 be used over and over again), giving the pulp a further bath in a very w^eak 

 alkali and thoroughly washing it, when the whole coloring matter comes away, 

 and a clean, fine and strong, light-colored pulp is left, which is now more 

 easily bleached than any other pulp now in use. No other ingredients 

 are necessary than those specified, which are of the cheapest possible descrip- 

 tion, and only a light electric current is required. The whole expense of the 

 intermediate process will not add, including the bleaching, more than |4 per 

 ton to the cost of the pulp. Both the process and the apparatus for producing 

 the solution (which makes use of a novel process in electrolysis) are patented, 

 and there is no other known means of fully bleaching matured bamboo, except 

 the antediluvian Chinese method of ''retting." 



