Hydrogen

hi'dro-jen, an element in the form of a gas, discovered in 1766 by Cavendish. It is without color, smell, or taste. It is not poisonous. Hydrogen is the lightest substance known. A balloon filled with hydrogen and set free will be forced upward with a bound by the heavier surrounding air. The weight of hydrogen is taken as a standard for gases. Thus we say the weight of hydrogen is 1 and that of oxygen 16. It may be burned in air, producing water. Hydrogen is difficult to confine. It passes through a stone jar or a brick or an ordinary plastered wall. In 1878 it was liquefied and frozen free, that is to say, uncombined. Hydrogen occurs in enormous quantities in the sun. It is found free in the openings of volcanoes and in certain salt mines and gas wells. It usually occurs in combination with other elements. It forms a trifle over one-ninth of water by weight. In addition to its presence as part of moisture, hydrogen enters into the tissues of all animal and plant life. See Oxygen; Water; Gas