It is mv belief that the natural sources are being rapidly worked 
out. Owing to the natural rubber trees and plants being scattered 
. over enormous areas, it is impossible to insist on a national treat- 
ment of the trees, and they are sure to disappear everywhere with- 
in a limited space of time. Hence future supplies must depend 
on plantations. 
Referring now to the second point, I am confident that to yield 
permanently a ton of rubber per year requires not less than ten acres 
of plantation. Hence to supply 65,000 tons a year, we require 
650,000 acres of plantation ; or allowing for some increase, 800,000 
acres. There is plenty of room for further extensions. 
The danger connected with this industry is the possibility of an 
efficient substitute for rubber being discovered. 
Oxford. W. SCHLICH. 
Most of the statements in this letter have been referred to over 
and over again in this Journal, and there is little need to go into 
them here. In my opinion Dr. Schlich arrives at a correct con- 
clusion. The only portion of the letter to which I must take 
serious objection is the part referring to yield of rubber per acre. 
“ To yield permanently a ton of rubber per year requires not less 
than ten acres of plantation.” It is now well known that trees of, 
say, 10 to 16 years of age, in suitable soil, etc., will give an average 
of 5 lbs. per annum. Taking the number of trees per acre at 135, 
this gives a yield of about 6 cwt. of rubber per acre. One ton per 
10 acres equals 2 cwt. per acre. 
The India Rubber Journal Vol. XXXI, p. 342. 
GROWTH OF THE RUBBER TRADE. 
A Reply to Dr. Schlich. 
To the Editor of the “ Times ” . 
Sir, — I consider it only as fulfilling a duty in writing to caution 
the public that no importance whatever should be attached to the 
entirely misleading figures given in Dr. Schlich’s letter, printed 
on page 94 of your “Financial Supplement” of March 12th. 
In the interest of those holding shares in tropical rubber com- 
panies I give the flattest possible contradiction to his statement 
“ that to yield permanently a ton of rubber per year requires not 
less than ten acres of plantation,” or that “to supply 65,000 tons 
a year we require 650,000 acres of plantation.” Previously to Dr. 
Schlich leaving India, in 1885, only the rubber from the Ficus 
elastica was collected and exported ; and if any rubber plantation 
then existed at all in India it was only of that particular sub-tro- 
pical kind (indigenous to Assam and Upper Burma), and not the 
Para or Brazilian rubber yielded by Hevea Braziliensis , and now 
cultivated largely in our tropical possessions (Ceylon, Malay States, 
Borneo, etc.). 
