It now occurred to him, that perhaps it was the turpentine used in dissolving the gum, or the lampblack employed to color it, that spoiled his product.  He esteemed it a rare piece of luck to procure some barrels of the sap not smoked, and still liquid.  On going to the shed where the precious sap was deposited, he was accosted by an Irishman in his employ, who, in high glee, informed him that he had discovered the secret, pointing to his overalls, which he had dipped into the sap, and which were nicely coated with firm India-rubber.  For a moment he thought that Jerry might have blundered into the secret.  The man, however, sat down on a barrel near the fire, and, on attempting, to rise, found himself glued to his seat and his legs stuck together.  He had to be cut out of his overalls.  The master proceeded to experiment with the sap, but soon discovered, that the handsome white cloth made of it bore the heat no better than that which was produced in the usual manner.

It is remarkable, that inventors seldom derive direct aid from the science of their day.  James Watt modestly ascribes to Professor Black part of the glory of his improvements in the steam-engine; but it seems plain from his own narrative, that he made his great invention of the condenser without any assistance.  Professor Black assisted to instruct and form him; but the flash of genius, which made the steam-engine what we now see it, was wholly his own.  The science of Glasgow was diligently questioned by him upon the defects of the old engine, but it gave him no hint of the remedy.  It was James Watt, mathematical-instrument maker, earning fourteen shillings a week, who brooded over his little model until the conception of the condenser burst upon him, as he was taking his Sunday afternoon stroll on Glasgow Green.  Goodyear had a similar experience.  Philadelphia has always been noted for its chemists and its chemical works, and that city still supplies the greater part of the country with manufactured drugs and chemists’ materials.  Nevertheless, though Goodyear explained his difficulties to professors, physicians, and chemists, none of them could give him valuable information; none suggested an experiment that produced a useful result.  We know not, indeed, whether science has ever explained his final success.

Satisfied that nothing could be done with India-rubber pure and simple, he concluded that a compound of some substance with India-rubber could alone render the gum available.  He was correct in this conjecture, but it remained to be discovered whether there was such a substance in nature.  He tried everything he could think of.  For a short time he was elated with the result of his experiments with magnesia, mixing half a pound of magnesia with a pound of gum.  This compound had the advantage of being whiter than the pure sap.  It was so firm that he used it as leather in the binding of a book.  In a few weeks, however, he had the mortification of seeing his elegant white book-covers fermenting and softening.  Afterwards, they grew as hard and brittle as shell, and so they remain to this day.