Gums, Resins, 342 [June 190?. 



discussion. " I noticed in working at rubber lately that in the first latex," he said, 

 "the latex contained 32 per cent of rubber, that is to say that for 3 lb. of latex 

 there was one 1 lb. of rubber ; but in all the latex sent to me recently, and from 

 what I hear from planters, the latex does not now equal that proportion, and the 

 caoutchouc has iu some instances gone down to 15 per cent, or less. It seems to 

 me the laticiferous tubes are refilled very rapidly, and the actual flow of water 

 into the tubes also is fairly rapid, but there is apparently a slight want of power 

 of formation of actual rubber in the latex, and this I think, must be carefully 

 watched in the future. The yield of the trees certainly has not fallen off ; but it 

 must mean that there is a much larger proportion of soft laticiferous tissue and 

 larger secretion of moisture which may possibly render the trees more liable to 

 attacks from insects. There is no knowing how this power of the actual formation of 

 the caoutchouc in the latex may fall off." 



Mr. Ridley's remarks on the subject of much interest . He states : ";It is of the 

 greatest importance to the cultivator in tapping to avoid tapping at the wrong 

 season when he is very liable to interfere with the special physiological processes 

 in the tree then performing their functions. The bark of the tree does not recover 

 as well from wounds during the resting period between December and March, nor 

 does it appear that the return of caoutchouc is as good. Too frequent or prolonged 

 tapping is not only injurious but produces a latex very inferior in its rubber- 

 producing qualities. This can only be due to actual bark injury." 



CAOUTCHOUC PRODUCTION AND BARK INJURY. 



"Although in over-tapping latex is renewed in the bark quickly, caoutchouc 

 takes much longer to produce, though it does not seem in the worst cases ever to 

 be entirely absent from the latex. The caoutchouc seems undoubtedly to be 

 directly or indirectly produced from the roots, but as the only injury to the tree 

 in tapping is caused to the bark of the trunk, it seems clear that it is the bark injury 

 only which reduces the amount of caoutchouc in the latex, for it does not seem 

 probable that the roots can be affected by the bark injury." 



Mr. Ridley is very insistent on the point of the ratio of rubber to latex, and 

 he concludes a most interesting and important report — to which we have not done 

 full justice in this notice— in the following paragraph : — 



"It cannot be too strongly pointed out that too frequent or prolonged 

 tapping is injurious and only produces inferior rubber. Even so recently as the 

 Ceylon Exhibition the discussions show that planters were quite satisfied with 

 prospective rubber crops as judged by the copious flow of latex, not appreciating 

 the fact that it is the quantity or ratio of caoutchouc to latex that alone constitutes 

 thereat crop and rich harvest. It will be remembered that in Brazil rubber trees 

 are only tapped for one period of the year ; doubtless owing to the country being 

 flooded. The longer interval of rest may represent well matured or well oxidised 

 caoutchouc and partly explain the preference for Brazilian rubber." 



WHAT'S WRONG WITH CEYLON RUBBER? 



A rubber manufacturer in Montreal (Canada), Mr. A. D. Thornton, writes aa 

 follows to the Editor of " The India Rubber World" : 



Is it not time that some one voiced a protest regardiug Ceylon rubber ? As 

 one who has followed this commodity rather closely, and as one of the earliest users, I 

 woud like to impart to your valuable journal my reasons for askingthe above question. 



When we first received samples of Ceylon rubber we were certainly struck 

 by its beautiful appearance, its cleanliness, and so on. We found its tensile strength 

 quite up to any Para ; for the purpose of making cement it was unequalled, because 

 it had a swell that figured up at least 7 per cent better than Para. 



