Collodion, as I have explained in previous chapters, is a solution in ether and alcohol of guncotton (otherwise known as pyroxylin or nitrocellulose), which is made by the action of nitric acid on cotton.  Hyatt tried mixing the collodion with ivory powder, also using it to cover balls of the necessary weight and solidity, but they did not work very well and besides were explosive.  A Colorado saloon keeper wrote in to complain that one of the billiard players had touched a ball with a lighted cigar, which set it off and every man in the room had drawn his gun.

The trouble with the dissolved guncotton was that it could not be molded.  It did not swell up and set; it merely dried up and shrunk.  When the solvent evaporated it left a wrinkled, shriveled, horny film, satisfactory to the surgeon but not to the man who wanted to make balls and hairpins and knife handles out of it.  In England Alexander Parkes began working on the problem in 1855 and stuck to it for ten years before he, or rather his backers, gave up.  He tried mixing in various things to stiffen up the pyroxylin.  Of these, camphor, which he tried in 1865, worked the best, but since he used castor oil to soften the mass articles made of “parkesine” did not hold up in all weathers.

Another Englishman, Daniel Spill, an associate of Parkes, took up the problem where he had dropped it and turned out a better product, “xylonite,” though still sticking to the idea that castor oil was necessary to get the two solids, the guncotton and the camphor, together.

But Hyatt, hearing that camphor could be used and not knowing enough about what others had done to follow their false trails, simply mixed his camphor and guncotton together without any solvent and put the mixture in a hot press.  The two solids dissolved one another and when the press was opened there was a clear, solid, homogeneous block of—­what he named—­“celluloid.”  The problem was solved and in the simplest imaginable way.  Tissue paper, that is, cellulose, is treated with nitric acid in the presence of sulfuric acid.  The nitration is not carried so far as to produce the guncotton used in explosives but only far enough to make a soluble nitrocellulose or pyroxylin.  This is pulped and mixed with half the quantity of camphor, pressed into cakes and dried.  If this mixture is put into steam-heated molds and subjected to hydraulic pressure it takes any desired form.  The process remains essentially the same as was worked out by the Hyatt brothers in the factory they set up in Newark in 1872 and some of their original machines are still in use.  But this protean plastic takes innumerable forms and almost as many names.  Each factory has its own secrets and lays claim to peculiar merits.  The fundamental product itself is not patented, so trade names are copyrighted to protect the product.  I have already mentioned three, “parkesine,” “xylonite” and “celluloid,” and I may add, without exhausting the list of species belonging to this genus, “viscoloid,” “lithoxyl,” “fiberloid,” “coraline,” “eburite,” “pulveroid,” “ivorine,” “pergamoid,” “duroid,” “ivortus,” “crystalloid,” “transparene,” “litnoid,” “petroid,” “pasbosene,” “cellonite” and “pyralin.”