Page:Popular Science Monthly Volume 1.djvu/675

Rh oxygen and hydrogen, which, with the characteristics of combustion, combine to form the well-known liquid. This fact was of such paramount importance, that at great expense a whole glass of water was produced by combustion, and the water was shown to possess the identical properties of pure rain-water.

In the beginning, chemistry, being still a young science, had to attend to domestic arrangements. It must first obtain the substances and contrive the apparatus wherewith to explore the natures of the various bodies composing our globe. A celebrated period soon followed, during which every number of a scientific journal would be filled with important and most momentous discoveries. So glorious an epoch as this probably never before occurred in the history of mankind. New elements, new compounds, were discovered—unknown compounds separated into their component elements. The discovery of the alkaline metals and earths was an event which astonished the world. The natures of such bodies as would not yield to analysis were divined, and subsequent experimentation has verified the speculations. Thus the presence of a metal in clay, lime, and quartz, was distinctly foretold; fifty years later it was actually produced.

The consequences of any discovery are incalculable. Davy investigated the nature of the flame, and communicated his discoveries in a lecture before a large audience. He demonstrated that it was within our power to produce a flame which, at a state of extreme heat, contained either free oxygen or unburnt carbon; that a large grate with a limited supply of coal would generate the former, the oxidizing flame, while a small grate with a larger amount of coal would yield the other, the flame devoid of oxygen, but in which combustible substances might be melted without the danger of combustion. Among the hearers sat a young man by the name of Cort, who directed his mind to these remarks. Up to that time cast-iron was converted into wrought-iron by heating it with charcoal and exposing the melted metal to a blast of air. By this process only small quantities of wrought-iron were obtained at a time, through the necessity of producing but one bloom in a heat, which might easily be hammered out; and also on account of the cost of charcoal. In this process mineral coal could not be placed in contact with the iron, because the never-failing presence of sulphur in that kind of coal would render the iron unfit for use. From Davy's lecture on the flame, Cort struck upon the idea of decarbonizing cast-iron without exposing it to the danger of the contact with coal, by allowing the flames only of the coal to play upon the cast-iron. Thus originated that wonderful operation called the puddling process. Large quantities of cast-iron are melted on the floor of a reverberatory furnace (so named from having an arch which throws the flame back on the iron), and a portion of the carbon in the iron is burnt up by the oxidizing flame; as soon as the iron passes from the liquid state to a pasty condition, the puddler rakes it by