To replace lead, of which Harding had found no traces in the island, he employed granulated iron, which was easy to manufacture. These bullets, not having the weight of leaden bullets, were made larger, and each charge contained less, but the skill of the sportsmen made up this deficiency. As to powder, Cyrus Harding would have been able to make that also, for he had at his disposal saltpeter, sulphur, and coal; but this preparation requires extreme care, and without special tools it is difficult to produce it of a good quality. Harding preferred, therefore, to manufacture pyroxyle, that is to say gun-cotton, a substance in which cotton is not indispensable, as the elementary tissue of vegetables may be used, and this is found in an almost pure state, not only in cotton, but in the textile fiber of hemp and flax, in paper, the pith of the elder, etc. Now, the elder abounded in the island towards the mouth of Red Creek, and the colonists had already made coffee of the berries of these shrubs, which belong to the family of the caprifoliaceae. The only thing to be collected, therefore, was elder-pith, for as to the other substance necessary for the manufacture of pyroxyle, it was only fuming azotic acid. Now, Harding having sulphuric acid at his disposal, had already been easily able to produce azotic acid by attacking the saltpeter with which nature supplied him. He accordingly resolved to manufacture and employ pyroxyle, although it has some inconveniences, that is to say, a great inequality of effect, an excessive inflammability, since it takes fire at one hundred and seventy degrees instead of two hundred and forty, and lastly, an instantaneous deflagration which might damage the firearms. On the other hand, the advantages of pyroxyle consist in this, that it is not injured by damp, that it does not make the gun-barrels dirty, and that its force is four times that of ordinary powder. To make pyroxyle, the cotton must be immersed in the fuming azotic acid for a quarter of an hour, then washed in cold water and dried. Nothing could be more simple. Cyrus Harding had only at his disposal the ordinary azotic acid and not the fuming or monohydrate azotic acid, that is to say, acid which emits white vapors when it comes in contact with damp air; but by substituting for the latter ordinary azotic acid, mixed, in the proportion of from three to five volumes of concentrated sulphuric acid, the engineer obtained the same result. The sportsmen of the island therefore soon had a perfectly prepared substance, which, employed discreetly, produced admirable results.