Gums, Resins, 



102 



[August, 1909. 



at present, it seems destined to have a 

 brilliant future, especially in those 

 fortunate districts where labour is cheap 

 and plentiful ; and it must not be for- 

 gotten that, if present estimates prove 

 correct and present prices continue, 

 each acre of ten-year-old rubber is 

 capable of yielding a profit of £50 per 

 acre. Sucn prospects are but rarely 

 held out by agriculture in any form, 

 either in tropical or temperate zones ; 

 and though few planters in South India 

 are sanguine enough to expect quite 

 such handsome returns as that, they 

 can, in our opinion, contemplate a fall 

 in prices with less concern than their 

 confreres in any other part of the 

 world. 



INDIA RUBBER AND ITS 

 MANUFACTURE. 



With Chapters ox Gutta-Percha 

 and balata. 



By Hubert L. Terry, 



(From the Review in Science, 

 December, 1908.) 



One may fairly say that, next to 

 mining, the growing of rubber has of 

 recent years been increasingly regarded 

 as a golden path to material ease. In 

 common with mining, the project has 

 its risks and drawbacks, and the only 

 safe guide to intelligent investment in 

 both is knowledge. This the general 

 public does not have, but many indivi- 

 duals desire specific information, either 

 for the reason observed, or for the sake 

 of general enlightenment. With regard 

 to rubber and its manufacture, Terry's 

 book fairly meets this need ; it is for 

 such that it has been written. Though 

 dealing with a distinctly technical field, 

 the author has succeeded in making a 

 very readable book, and this is due not a 

 little to his pleasing style, occasional pro- 

 lixity to the contrary notwithstanding. 



One experiences a slight feeling of 

 disappointment in reading the first two 

 chapters, those dealing with the history 

 of the matter and with the botanical 

 origin of crude rubber. It would have 

 been justifiable to have dealt with these 

 topics with greater liberality, and the 

 addition of treatment of greater length 

 of the cultural aspects of the industry 

 would have heightened the value of 

 the book in a marked degree. It seems 

 to the reviewer a fair criticism that the 

 chapter on India-rubber Plantations is a 

 trifle pessimistic. Mr. Terry's attitude 

 is safe, because negative. A more just 

 statement of the legitimate attempts 

 which are being made in Mexico to 



cultivate rubber trees (Castilloa) would 

 have had greater merit. Sharp practices 

 do great damage to infant industries. 

 So much more therefore do these demand 

 proper representation at the hands of 

 the critic- 



To be commended in this connection 

 is the effort to point out the need for 

 adequate conservation of the natural 

 forests of rubber-prpducing trees, a 

 problem to which our modern forestry 

 methods have not yet reached. Science 

 will be needed in meeting this aspect of 

 the industry quite as much as any other. 

 Already her face has been turned toward 

 plantation culture, with no little success, 

 but the inevitable struggle of man with 

 nature has already discovered a quite 

 handsome array of parasitic enemies, 

 whose energies appear to be largely con- 

 centrated upon cultivated rubber trees. 



PLANTATION RUBBER YIELDS. 



(From the India Rubber World, 

 January, 1909.) 

 The latest mail advices to haud at this 

 writing report the shipment from Ceylon 

 and Malaya, during something less than 

 eleven months of this year, of 3,401,734 

 pounds of plantation rubber. The 

 figure for the corresponding period of 

 1907 was 1,935,103 pounds, and for the 

 preceding year 908.965 pounds. Five 

 years ago the amount was almost nil. 

 The rapid growth in the volume of ship- 

 ments evidently is due (1) to the increas- 

 ing number of tappable trees, and (2) 

 to an increased annual yield from those 

 trees which have now been tapped for 

 three or four seasons. It seems worth 

 while to emphasize, in this connection, 

 that in the mass of information that 

 has come from the Hevea planting region 

 of the Far East — reports so detailed as 

 almost to suggest that every individual 

 rubber tree has been scrutinized — no 

 hint has appeared that one tree on 

 suitable soil has failed to yield some 

 rubber, or that any tree, once tapped, 

 has failed to yield at subsequent tap- 

 pings. 



Thus far it has not been possible, how- 

 ever, to fix upon a definite minimum 

 yield to be expected reasonably from 

 a cultivated rubber tree, of any given 

 age or size. But this is hardly essential. 

 Is there a fixed law of yield of tea or 

 coffee plantations, or of wheat or corn, 

 or of grapes or pears ? It is enough if, 

 generally, the product per acre, or 

 for a whole estate, affords a profit. The 

 figures given above show that cultivated 

 trees do yield rubber, and details con- 

 stantly coming forward indicate an aver- 



