Since I am here chiefly concerned with "Creative Chemistry," that is, with the art of making substances not found in nature, I have not spoken of shellac, asphaltum, rosin, ozocerite and the innumerable gums, resins and waxes, animal, mineral and vegetable, that are used either by themselves or in combination with the synthetics. What particular "dope" or "mud" is used to coat a canvas or form a telephone receiver is often hard to find out. The manufacturer finds secrecy safer than the patent office and the chemist of a rival establishment is apt to be baffled in his attempt to analyze and imitate. But we of the outside world are not concerned with this, though we are interested in the manifold applications of these new materials. There seems to be no limit to these compounds and every week the journals report new processes and patents. But we must not allow the new ones to crowd out the remembrance of the oldest and most famous of the synthetic plasters, hard rubber, to which a separate chapter must be devoted. VIII THE RACE FOR RUBBER There is one law that regulates all animate and inanimate things. It is formulated in various ways, for instance: Running down a hill is easy. In Latin it reads, _facilis descensus Averni._ Herbert Spencer calls it the dissolution of definite coherent heterogeneity into indefinite incoherent homogeneity. Mother Goose expresses it in the fable of Humpty Dumpty, and the business man extracts the moral as, "You can't unscramble an egg." The theologian calls it the dogma of natural depravity. The physicist calls it the second law of thermodynamics. Clausius formulates it as "The entropy of the world tends toward a maximum." It is easier to smash up than to build up. Children find that this is true of their toys; the Bolsheviki have found that it is true of a civilization. So, too, the chemist knows analysis is easier than synthesis and that creative chemistry is the highest branch of his art. This explains why chemists discovered how to take rubber apart over sixty years before they could find out how to put it together. The first is easy. Just put some raw rubber into a retort and heat it. If you can stand the odor you will observe the caoutchouc decomposing and a benzine-like liquid distilling over. This is called "isoprene." Any Freshman chemist could write the reaction for this operation. It is simply C_{10}H_{16} --> 2C_{5}H_{8} caoutchouc isoprene That is, one molecule of the gum splits up into two molecules of the liquid. It is just as easy to write the reaction in the reverse directions, as 2 isoprene--> 1 caoutchouc, but nobody could make it go in that direction. Yet it could be done. It had been done. But the man who did it did not know how he did it and could not do it again. Professor Tilden in May, 1892, read a paper before the Birmingham Philosophical Society in which he said: