Vol. XIV. No. 338. 



THE AGRICULTURAL NEWS. 



127 



The cautioD must be repeated that all these measures 

 depend entirely for their success mi the conditions being 

 right for the development of the I ngua. fn drj weather 

 are useless. Moreover, experiments have shown that 

 i fungus has been giver i i J start, attempts to 



increase its efficiency by furthei ore-spraying often have 

 little \ isible effect. 



The possibility, in some situ oi altering the con 



ditions so as to favour fungous control by providing wind 

 breaks or other forms of shelter should not I"- lost sight of. 



Caution should be observed in making use ol infested 

 material lest scale insects not di present on the p 



should be introduced. Leaves of grape-fruit recently col 

 I, on which the scales were well infested with three 

 of fungi, nevertheless had numbers of the young of 

 the mussel scale crawling over them more than a week after 

 they were picked and dried. 



VV.N. 



CELLULOSE FROM THE BAMBOO. 



In view of the fact that some attention is being given in 

 Trinidad to the utilization <>f the bamboo as material for 

 paper making, considerable interest attaches to a communi 

 cation madebj Mr. William Raitt, Cellulose Expert, Imperial 

 Forest Research [nstitute, India, to the Eighth International 

 Congress of Applied Chemistry. In the article under con- 

 sideration it is stated that it has been proved that bamboo 

 cellulose is suitable for the manufacture of paper, especially 

 for the printing and litho grades, provided its isolation has 

 been successfully accomplished. Previous to the investigation 

 with which the article deals, some divergency of opinion 

 existed in regard t<> the possibility if utilizing nodes and 



in operations connected with isolation. 



The writer refers to Mr. R. S. Pearson's work in con 

 nexion with the specie- of Bambusa suitable for paper-making 

 material in India and Burma. Out of some hundred different 

 species, only five were found to be suitable, namely, B. Tulda, 

 B. arundinacea, II. polymorphs, B. [Cephalostachyum] perga- 

 rile, and B. [Melocanna] bambusoides. These are the only 

 species which exist in commercial quantities and under 

 economically exploitable conditions. Though few in number, 

 these species are each so dominant in its own area that 

 they probably represent 80 per cent, of the whole growing 

 stand of bamboo in the country. 



The point next dealt with is the difficulty of distinguish- 

 ing band stems of different ages. The writer then proceeds 



to consider the digestion of the stems. It is stated that the 

 material lias an undesirable tendency to float. Its resistance 

 to penetration and the variation of this in accordance with 

 ze of the chip is indicated Uso there is the variation 

 in this respect in accordance with age, a charge of mixed age 

 ng invariably irregularly digested. 



A band lolumn is light and buoyant solely because it 



U hollow. [ts component wood is really as heavy as many 

 of our commercial hardwoods. Its actual specific gravity 

 somewhat with species, that of the lightest of the 

 five species we are concerned with being '8410 for inter 

 nodes, and '8091 for nodes, while the heaviest is '9555 

 internodes,. and '9170 node-. Bomboo is therefore of about 

 twice the specific gravity of thi on pulp woods, spruce 



and fir — i fact which when realized iii all its bearings, throws 



considerable doubt i • whether we ha right in 



ting ii on similai lim is v ' r as its preliminary 



preparation for digest iot :oi I 



A marked mien -. opii feature "t baml is the 



els which run con I from top to bottoi 



ni8. These do not collapse in diving, but retain their full 



size and shape, and con 



I >rj baml is theref d h 1th air in 



a state of capillarity i condition which nuke- it 3omewl 

 difficult to expel, and which fully accounts for the tendency 

 to float, which is one ol b.ief < ion. 



I ligestion difficulty ari lerefore d the 



capillary air and to a i c 3ti ucl ural u to p 



tration of liquor varying with the size of the individual chip. 

 The .smaller the particles and the moo ize, the 



better will be the results. Some light is thrown upon 

 resistance by a chemici imination of the stem. Ii was 



found that lignification begins with the sprouting of h 

 branches which occurs when the culm is three-fourths grown, 

 and is complete at i year old, little oi no cl his 



respect happening aftet df-grown I he 



plant is wholly pecto-cellulose in character. With the rapid 

 increase in lignin at maturity, there is a corresponding reduc 

 tion in pectose, but with advancing age a gradual increase in 

 the latter at the expense of the starch group. The plant is 

 distinctly of a pecto-ligno-cellulose character. 



The investigation into the amount of can-tic soda needed 

 for digestion showed thai the wide stem, nodes included, 

 when suitably crushed, will digest satisfactorily with a theori 

 tical IT. 1 , to 18 per cent, of NaOH, and it makes no differ- 

 ence whether it is one or three years old, and in the produce 

 there is absolutely no indication whatever of the nodes. It is 

 pointed out that under normal conditions of digestion, pectose 

 gelatinizes, and probably resistance is set up; but crushing 

 counteracts -uch action in the case of bamboo. 



One of the remaining difficulties is connected with thi 

 starch content of the plant, and its effect upon yield oi 

 cellulose and also on the bleaching results. It was found that 

 starch in the bamboo is capable of being oxidized by air and 

 dispersed in the atmosphere, and that such oxidation is an 

 integral part of the process of seasoning. This has led to the 

 conclusion that the maximum yield of cellulose can only be 

 obtained from bamboo which is not merely dry, but is also 

 seasoned. The influence of the standi content upon bleaching 

 is due to the results of the combination between it and 

 NaOH which occurs under the digestion conditions of 

 strong liquor and high temperature. This .Iocs no harm if it 

 were not for the fact that the secondary starch contains an 

 insoluble dark-brown precipitate, which is unreachable .vitliiu 

 economic limits. This was removed satisfactorily by means 

 of the sulphite process. A 1-per cent, solution applied in 

 simple cold steeping to the unbleached pulp produced by 

 NaOH, dissolved out of it a large quantity of dark-brown 

 colouring matter, leaving it several shades lighter in colour 

 and much more bleachable. 



In conclusion, the objections that have been made to 

 bamboo as a paper making material, and the difficulties 

 hitherto met in their treatment as described in the above 

 article can be met in the following waj oned bamboo 



only to be used: (b) raw material to be crushed; (c) water 



soluble matter to I \traeted previously to digestion; 



(d) digestion with sulphite liquor. It is pointed out that 



the foregoing refer only to the five species of India and 



Burma, and may not prove altogether applicable to t In- 

 bamboos of other species grown elsewhere. 



