37i 
important observation that when isoprene 'prepared from oil of 
turpentine is kept for sometime, it gradually passes into a substance 
having all the characteristic properties of Caoutchouc.” Professor 
DuNSTAN then points out that chemistry holds the key to the future 
of the rubber industries in all their phases. '‘The discovery of better 
methods of coagulation, preparation and purification will be effected 
through chemical investigation as will also the determination of the 
manner of utilizings the various ether plants which furnish rubber 
like latices. That the physical properties of raw rubber on which 
its technical value depends are to be correlated with the chemical 
composition of the material there can be no doubt. The chemical 
analysis of raw rubber as at present conducted is however not 
always to be taken by itself as a trustworthy criterion of quality 
and more refined processes of analysis are now needed. Although 
the finest Caoutchouc for technical purposes is only yielded by some 
half-a-dozen plants under the name of which these varieties of Caout- 
chouc pass there can scarcely be a doubt that the elastic substance 
in each case possesses a very similar if not identical chemical 
structure. Nearly all the latices and similar fluids supplied by 
plants contain more or less Caoutchouc. Even opium, the dried 
juice of the capsule of the poppy contains Caoutchouc, whilst the 
opium yielded by certain Indian species contains a notable pro- 
portion. Chemistry must determine the means by which Caout- 
chouc can best be separated from these relatively poor latices. In 
view' of the increasing production of the nearly pure Caoutchouc 
which is furnished by Hevea, Funtumia , Castilloa and Ficus elastica , 
and a few other plants which occur or can be cultivated in several of 
our tropical possessions, the question is not a pressing one at the 
moment. 
The production of Caoutchouc by chemical means has been vir- 
tually accomplished in its formation from isoprene. The exact 
nature of this change has still to be determined. When this has 
been done it will only remain to cheapen the cost of production, to 
make the manufacture of synthetic rubber a purely practical pro- 
blem. 
It has to be remembered that the actual cost of producing raw 
rubber which is at present about a shilling a pound will probably be 
reduced and the market price of rubber may be so considerably 
lowered that as with quinine the synthetic production could not 
profitably be carried on. Chemists may, however, confidently predict 
that before the British Association again meets at York, the synthe- 
tic production of rubber will be a fully accomplished fact.” 
He then refers to the vulcanising of rubber and to the recent 
experiments of Mr. Bamber in vulcanising fresh latex, and says 
that if this proves to be practicable it may mean the transference 
to the tropics of the vulcanizing industry. 
I have quoted at length from this very important and interesting 
paper, not on^ because of its intrinsic interest, but because it so 
frequently happens that persons interested in rubber or other indus- 
tries frequently see only a garbled account of such investigations 
7 }l*Q 
I I * 
