It has been said by some that the discoveries made by the alchemists were mainly the result of chance, and they were mostly ignorant charlatans; but although they had little method in their research, and a great deal of their knowledge was wrapped up in absurd and superstitious theories, when we look at the result of their discoveries up to the fifteenth century, the most prejudiced must admit that their labours were not spent entirely in vain. They demonstrated the existence of bismuth, liver of sulphur, and regulus of antimony, the distillation of alcohol, volatilisation of mercury, and preparation of aqua regia, sulphuric and other mineral acids, and the purification of alkalies. They had the scarlet dye for cloth, the secret of which has now been lost and cannot be equalled, and their processes of glass-staining cannot be approached by those employed at the present day. It is said that Eck, a German alchemist of Sultzbach, ascertained the existence of oxygen 300 years before it was demonstrated by Priestly. For these and other discoveries we have to thank the early alchemists. During the fifteenth and sixteenth centuries alchemy began to shake itself free from the wild theories and absurd practices which had impeded its progress. Henry VII. issued a severe edict against alchemical practices, which put a stop to the impositions of a number of charlatans. About this period John Baptist Porta discovered the means of reducing the metallic oxides and of colouring silver, and Isaac and Jean Hollandus made great improvements in enamelling, and demonstrated the manufacture of artificial gems. From the time of Paracelsus and the introduction of printing, the science received a fresh impetus, and a new order of chemists came into being, whose conflict with the old order for many years is a matter of history. The old theories of the alchemists were gradually exploded and superseded, and many were driven to the most flagrant quackery to earn a living. Cornelius Agrippa, who was one of the leaders of the new order, says: “It would take too much time to recount all the follies, the idle secrets, and the enigmas of this trade, of the green lion, the fugitive stag, the flying eagle, the inflated toad, the crow’s head of the black blacker than the black, of the seal of Mercury, of the mud of wisdom, and other countless absurdities of the time. Many of them travelled from fair to fair in order to make a little money by the sale of white lead, vermilion, antimony, and other drugs used by women for painting the face, and drugs which the Scripture calls ointments of lust.” Meanwhile the efforts of the practical workers were encouraged by administrators and princes, with the result that the application of chemistry and the technical arts became predominant, and metallurgy the leading spirit of the science.