Gums, Resins, 



482 



[June, 1910. 



The opening of the Experiment Station 

 at Maha-iluppalania in the North-Central 

 Proviuce, in the midst of a chena 

 country, has given us the opportunity 

 really to study this question. The land, 

 we were assured by the local villagers, 

 was only fit lor chena, but the first 

 glance at the excellent soil showed that 

 this idea was probably absurd. As a 

 matter of fact, we have cultivated it 

 continuously since the N.B. rains of 1904, 

 or six years consecutively, and the crops 

 are as good as ever they were. 



The real truth of the chena proposi- 

 tion would appear to be this. The 

 moneyless native clears and burns off 

 the land, and puts in his first crop, 

 which is often a " bumper." He usually 

 tries a second, but the weeds are now 

 getting a firm hold, and greatly reduce 

 the yield, while in a third season it is 

 very commonly hopeless to expect any 

 crop, because of the growth of weeds. 



The land is therefore abandoned, and 

 slowly a shrubby growth appears on it, 

 and as it gets taller, the weeds of open 

 ground slowly disappear, and are re- 

 placed by the weeds of shady ground, 

 which when the land is again opened 

 will disappear. And by leaving the 

 land alone some years, not only do the 

 weeds of open ground, which were so 

 troublesome, disappear, but a large 

 proportion of their seeds also die, so 

 that when the land is again re-opened it 

 is not at once covered by these weeds. 

 After 8 to 50 years the chena process is 

 repeated, most often in the wettest 

 regions, where the growth upon the 



chena most rapidly reaches height and 

 density. 



All our work at Maha-iluppalama goes 

 to show that chena land may be kept in 

 a state of continuous cropping, provided 

 that the weeds are kept down. This of 

 course necessarily means much greater 

 expenditure upon weeding. Allowing 

 for the fact that the chena cultivator as 

 a rule does not injure his health by 

 excessive devotion to work, it is prob- 

 able that he might be able to keep his 

 chena under crop, but he would likely 

 have to reduce the area. But he would 

 also have to spend more on tools, fenc- 

 ing and other things, and therefore 

 must necessarily have more command of 

 money than he has at present. 



Chena in private hands cannot of 

 course be interfered witb, though every 

 encouragement should be given to 

 experimenting with continuous crop- 

 ping, rotation of crops, permanent crops, 

 and the like. But it may be suggested 

 that no chena be allowed on public land 

 unless part of the land be properly holed 

 and planted with coconuts or other per- 

 manent crops, at distances of say 30 ft,, 

 this crop to become the property of the 

 Goverrment. Many of the trees would 

 doubtless die, but many would grow 

 properly, and the land become of per- 

 manent value. 



As the population increases, and the 

 people are driven to harder and less 

 casual work, chena necessarily dis- 

 appears, and it is in this way that its 

 final exit must probably be looked for 



J. C. W. 



GUMS, RESINS, SAPS AND EXUDATIONS. 



SYNTHETIC RUBBER. 



(Prom the Chemist and Druggist, No. 1, 

 574, Vol. LXXVL, March 26, 1910.) 

 " De Indische Mercuur" of March 8 

 published some particulars of the work 

 done by the Synthetic Rubber Co., which 

 was formed in this country about three 

 years ago to investigate various pro- 

 cesses proposed for the manufacture of 

 synthetic rubber. The company first of 

 all examined the Gottschalk process, 

 and this was speedily disposed of, as it 

 was found impossible to produce rubber 

 by it, . Attention was then directed to 

 the Heinemann process, which also 

 proved to be valueless, after £1,000 

 had been expended in experiments with 

 it. At this stage the company undertook 

 research work on its own account, and at 



one time it seemed to be on the high 

 road to success. At a meeting held in 

 March, 1909,the President announced that 

 they were in possession of a satisfactory 

 method of making rubber, and a call on 

 the shareholders was made in order to 

 defray the cost of large-scale trials. 

 This process is believed to be that 

 invented by Liley, of Oxford University. 

 It is understood that this actually 

 yields a product having the chemical 

 and physical properties of rubber, but 

 that the cost of production is so high as 

 to render its working unremunerative 

 under present conditions. The article 

 continues with the remark that it is not 

 impossible that a syntehtic rubber may 

 be made eventually, but that until the 

 price of natural rubber rises to about 

 20s. per lb,, it is very improbable that it 



