“What else is there in ashes? A short account of the matter will tell us. In 1669 there lived in Hamburg, Germany, a learned old man named Brandt, whose head was a little turned and who sought to turn common metals into gold. From old iron, rusty nails, and worn-out kettles, he hoped to produce the precious metal. But he did not succeed in his endeavors, nor was it destined that he should succeed, for the simple reason that the thing is impossible. Never is one metal changed into another. When he was about at the end of his resources he took it into his head to conceive a crowning absurdity. He imagined that in urine would be found the ingredient capable of turning all metals into gold. Behold him, then, boiling urine, evaporating it, and cooking the disgusting sediment, first with this, then with that, until at last one evening he saw something shining in his phials. It was not gold, but something more useful: it was phosphorus, which to-day gives us fire. Don’t make fun of old Brandt and his foolish cooking: in seeking the impossible he made one of the most important discoveries. To him we owe the sulphur match, that precious source of light and fire so easily and quickly used. “If you examine a sulphur match you will see that the inflammable tip contains two substances: sulphur, laid on to the wood, and another substance added to the sulphur. This last is phosphorus, colored with a blue, red, or brown powder, according to the caprice of the manufacturer. Phosphorus by itself is slightly yellow in color and translucent like wax. Its name means ‘light-bearer.’ When rubbed gently between the fingers in the dark, it does indeed give out a pale gleam. At the same time there is a smell of garlic; it is the odor of phosphorus. This substance is excessively inflammable: with very little heat or with slight friction against a hard surface, it catches fire. Hence its use in the manufacture of matches. “Phosphorus is a horribly poisonous substance. By melting a little of it in grease a poison can be obtained that will destroy rats and mice. Crusts of bread are smeared with this composition and exposed in places frequented by these animals. A nibble is enough to ensure speedy death. Hence you perceive that because of their poisonous nature matches are to be handled with extreme care. Contact with food might produce the gravest consequences.” CHAPTER VII PHOSPHATES AND NITROGEN “Phosphorus, which is a dangerous poison, as we have seen, is nevertheless found in abundance in the bodies of all animals. It occurs in the urine, whence Brandt was the first to extract it; it is found still more plentifully in the bones, and from thence it is now obtained. There is some in meat, in milk, and in cheese; also in plants, notably cereals; hence flour and bread contain it. But do not be alarmed: we shall not die of poison like the rats that have nibbled crusts smeared with grease and phosphorus.”