480 QUEENSLAND AGRICULTURAL JOURNAL. [1 Juxx, 1898. 
The next phase of the subject introduces Mons. Eugene Serullas, who went 
to Perak to consult with Mr. Wray on this subject. Mr. Wray accompanied 
M. Serullas into the jungle and showed him the rubber-trees, and also gave 
every aid in his power to the French scientist to test his new invention for the 
extraction of the gum. i 
The process is as follows :—The twigs and leaves of the gutta-tree, which 
are obtained by way of ordinary pruning, having been brought into the store 
in bundles, are finely chopped up. It is a matter of no moment apparently 
whether the leaves, &c., are still fresh or dead. The chopped-up stuff is then 
treated with acid (which is the main secret of the invention) until a reddish- 
brown liquor is produced. This is put into an alembic, already supplied with 
a small quantity of water, to prevent the gutta from sticking to the sides of 
the vessel, and steam is applied for about twenty minutes or half-an-hour, 
during which the acid evaporates and is drawn off. When the experiment 
was made by M. Serullas in the presence of the Governor of the Straits 
Settlements, it was concluded rather too soon, through a desire not to keep His 
Excellency waiting too long. But there was the gutta, rather more than 1 lb, 
of it, extracted from 380 Ib. of the chopped-up leaves and twigs. When the 
process has been perfected it is expected that the proportion of 2 per cent. at 
least of pure gutta will be obtained from the raw material. 
When in 1892 Messrs. Rigole and Serullas took out a patent for their 
process, the secret acid was found to be merely bisulphide ot carbon, a well- 
known solvent of gutta-percha. Since then, in 1896, large orders were 
received by Messrs. Chasseriau Bros. for dry leaves (up to 1,000 pikuls per 
month) for an unlimited time at 4 dollars per pikul, and subsequently raised 
the quantity to 8,000 pikuls per month at 4°50 dollars per pikul. Since, 
however, Mr. Wray’s paper appeared he has received information on what 
appears to be good authority that the agents in Singapore had stopped buying 
the leaf, the reason being that there is no sale for gutta-percha extracted by 
the bisulphide process. It was found on working it up to be of very inferior 
quality, doubtless due to the conversion of part of the gutta into resin in the 
tissues of the leaves during the time which elapses between collecting them 
and extraction in Europe. it is also quite possible that the process itself may 
have a deleterious effect on the gum. ; 
In any proposal to cultivate rubber-trees, the extraction of gum from 
every part of them should be considered. It is also quite possible that the 
trees might be shaved or stripped of their bark in the same way as is the 
practice with cinchona-trees. 
The Pharmaceutical Journal of 29th June, 1895, on the annual report of 
the Botanical Gardens at Buitenzorg (Java), gives some useful information on 
the point :—‘‘Some interesting experiments made on the leaves of the gutta- 
percha plants—namely, Palaguium borneensis and P. gutta—showed that the 
young leaves yielded respectively 6°5 and 5°7 per cent. of pure white gutta, the 
mature leaves 48 and 6:33 per cent., and fallen leaves 8 per cent. and 8:24 per 
cent., showing that the P. gutta is practically the richer of the two. ‘Lhe 
larger percentage in the fallen leaves is attributed to the destructive action of 
the sun and rain upon the tissues.” 3 
The question arises, Will these trees stand coppicing, and at what age 
could they be cut down without killing the stumps? Actual experience only 
can decide the point. Professor Ramsay says that the tree always comes up 
again when cut down. It can be cut to within 6 inches of the ground, and will 
then throw up shoots. Were it not for this, there would hardly be a single 
specimen in the country. It grows slowly in this manner, but never fails to 
come up again. 
The portion of the tree containing the most gutta, and which is the easiest 
to handle, is the bark, and it is this which would be the main source of supply, 
though, of course, others should not be neglected. 
