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DECEMBER 27, 1906| 
NATURE Sa 
RUBBER CULTIVATION IN THE EAST, AND 
THE CEYLON RUBBER EXHIBITION. 
N exhibition of ‘‘ rubber ’’ has lately been held in the 
Royal Botanic Gardens at Peradeniya, in Ceylon, 
with the most unqualified success, and the time is oppor- 
tune to see where we stand, and to sum up the worl of 
the scientific institutions which have been engaged in 
starting this new, and now very prosperous, industry. 
Rather more than thirty years ago it began to be evident 
that there was a possibility that, as in the previous case 
of cinchona, the natural wild rubber supplies—which were 
then almost solely South American—would in time be 
exhausted, and an expedition was sent by the Indian 
Government, aided by the Royal Botanic Gardens at Kew, 
to the valley of the Amazon, where seeds and plants of 
the Para rubber—Hevea brasiliensis—and other rubber- 
yielding plants were obtained and safely conveyed to Kew. 
From Kew they were sent to the East, and as it was 
fairly evident that at that time there was no place in 
India suitable for their growth, they were sent to the care 
of Dr. Thwaites, in Ceylon, the then director of the 
‘botanic gardens in that colony. A few were also sent to 
Singapore and elsewhere. These plants arrived in Ceylon 
in 1876, and were planted chiefly in the low-lying garden 
of Henaratgoda, which was specially opened for their 
reception. 
The trees began to seed about 1882, and from that time 
onwards practically all the seed has been used. Of the 
earlier crops a large part was sent to 
essential elements in the smoke used in South America 
were acetic acid and creosote, and Parkin applied this to 
the preparation of rubber in the East by collecting the 
latex in tins containing a little water (to prevent immediate 
coagulation) and mixing it with the calculated quantity 
of acetic acid and a little alcoholic solution of creosote. 
The milk being filtered before treatment, the result was 
to clot it into a perfectly clean ‘‘ biscuit,’? which, when 
rolled out and dried, gave more than 93 per cent. of 
caoutchouec, a much higher proportion than had ever before 
been found in any sample of crude rubber. These biscuits 
were analysed by Messrs. Michelin and Co., of Clermont- 
Ferrand, and after going through the washing machine 
emerged 99 per cent. to 100 per cent., against about 80 per 
cent. for any of the best wild rubbers. 
This work caused a still further demand for rubber 
seed, but it was still only in limited supply, though the 
older trees upon private estates were now beginning to 
come into bearing, and by 1902 there was almost unlimited 
seed available. At the same time a demand was also 
springing up in the Malay Peninsula, stimulated by the 
action of the director of the botanic gardens at Singapore 
(Mr. H. N. Ridley), who has steadily pushed rubber for 
many years. 
For the next three or four years planting went on 
slowly, and then about the latter half of 1902 began to 
be rapid, with the increasing supply of seed. By the 
middle of the present year, 1906, there were in Ceylon 
alone more than 104,000 acres of land planted in rubber, 
other countries, but in later years 
most of the seed was used in the 
island. In 1888 the late Dr. Trimen, 
Thwaites’s successor, began to tap 
one of the original trees at Henarat- 
goda, and in that year, working in 
the rough way then practised, 
r lb. 12 oz. of dry rubber were 
obtained from it. V-shaped cuts were 
made with a chisel, and the milky 
latex allowed to run. down into cocoa- 
nut shells and to dry naturally. The 
tree was given a rest in 1889, and in 
1890 gave 2 lb. 10 oz. It was again 
tapped in every second year following, 
and by 1896, in which year the experi- 
ment came to an end, it had yielded 
13 lb. 7 oz. in the five tappings, and 
was twenty-two years old. The aver- 
age yield was thus about 1 Ib. a year, 
but the tree was twelve years old 
when the experiments began, and was 
also, instead of being of the average 
size, the largest tree in the plantation. At this rate, there- 
fore, there was but little prospect for success, especially 
with the price at the comparatively low figure which it 
then occupied. 
The next stage in the work was in 1897, when the 
writer found that the average yield of a plantation of 
trees about twelve years old might be about 120 lb. an 
acre, and also made the very important discovery of the 
““ wound response.”’ It is found that the second tapping 
of a given area, provided it is made within about ten 
days, will yield a larger flow of latex than the first. 
Thus, in the experiments just mentioned, the average 
yield per tree in the first week was 0-73 0z., in the second 
week 1-48 oz., in the third 0-97 oz., fourth 0-80 oz., and 
only in the fifth did it fall below that obtained in the | 
first week, being only 0-67 oz. This is a discovery of 
very great importance, and one of which a scientific ex- 
planation is very desirable. From these figures it was 
calculated that a rubber plantation might show a profit 
of 27 per cent. at the tenth year, and with this the taking 
up of the industry began in Ceflon, being handicapped 
only by the very limited supply of seed. 
In the following year Mr. John Parkin came out to 
Peradeniya as assistant, and was at once started to work 
at rubber. He worked out the whole question of the 
wound response, and, further, worked out in detail a new 
method of preparing rubber in far purer condition than had 
Previously been the case.  Biffen had shown that the 
NO. 1939, VOL. 75] 
| scale as yet. 
oe ime rn 
4 
Buildings of the Rubber Exhibition held at Peradeniya, Ceylon, on September 15-27. 
almost solely the Para variety. Of the other South 
American rubbers, the Ceara sort, Manihot Glaziovii, was 
largely planted in Ceylon in the early ‘eighties, but never 
quite realised expectations, and has never been more than 
a minor crop, though the export has never actually ceased. 
The other, Castilloa elastica, is a very puzzling tree as 
yet. It grows with great rapidity at first, and then slows 
down, and though it yields very freely at first tapping, 
it has no wound response, and dies if too severely handled. 
It has only, consequently, been planted on a very small 
Para rubber, on the other hand, seems to 
grow freely up to a small elevation in any part of ‘* wet” 
Ceylon, and can be very roughly handled without, so far 
as can be seen, suffering any serious injury. None of 
the other rubber-yielding trees has given remunerative 
returns. 
Not only are there already so many acres in Ceylon, 
| but the Malay Peninsula has about 50,000 or 60,000 acres, 
and many other eastern countries have also considerable 
areas, all practically under Para rubber only, while in 
the west, Mexico has, it is said, about 20 millions of 
trees of Castilloa planted, or, allowing 200 trees to the 
acre, an area of about 100,000 acres. This we believe to 
be an overestimate, but at any rate there is a very large 
area in that country. Altogether it is probable that at 
the present time there are about 275,000 or more acres 
planted to rubber. Allowing that the Para rubber yields 
twice as much as the Castilloa, this will represent about 
