understood him in English. He laid full emphasis upon German
achievements and cast doubt upon the claim of "the Englishman Tilden" to
have prepared artificial rubber in the eighties. Perkin, of Manchester,
confronted him with his new process for making rubber from potatoes, but
Duisberg countered by proudly displaying two automobile tires made of
synthetic rubber with which he had made a thousand-mile run.

The intense antagonism between the British and German chemists at this
congress was felt by all present, but we did not foresee that in two
years from that date they would be engaged in manufacturing poison gas
to fire at one another. It was, however, realized that more was at stake
than personal reputation and national prestige. Under pressure of the
new demand for automobiles the price of rubber jumped from $1.25 to $3 a
pound in 1910, and millions had been invested in plantations. If
Professor Perkin was right when he told the congress that by his process
rubber could be made for less than 25 cents a pound it meant that these
plantations would go the way of the indigo plantations when the Germans
succeeded in making artificial indigo. If Dr. Duisberg was right when he
told the congress that synthetic rubber would "certainly appear on the
market in a very short time," it meant that Germany in war or peace
would become independent of Brazil in the matter of rubber as she had
become independent of Chile in the matter of nitrates.

As it turned out both scientists were too sanguine. Synthetic rubber has
not proved capable of displacing natural rubber by underbidding it nor
even of replacing natural rubber when this is shut out. When Germany
was blockaded and the success of her armies depended on rubber, price
was no object. Three Danish sailors who were caught by United States
officials trying to smuggle dental rubber into Germany confessed that
they had been selling it there for gas masks at $73 a pound. The German