LIQUEFIED AND COMPRESSED GASES. Introductory Statement.— Matter, that is all physical substance, commonly is understood to exist in three forms, solid, liquid and gaseous. Under ordinary conditions this is a true concept but it is not generally appreciated that in reality matter may be changed from one form to another, that a solid under one con dition of temperature and pressure becomes a liquid at another,. and a gas at a third. Con versely a gas by similar changes in temperature and pressure may be converted into a liquid or a solid. The earth typifies all matter, its crust being composed of solids, its oceans, lakes, rivers and in part its molten interior liquids, and its atmosphere and the vapors pent up within its interior, gases. The genius of mankind in the past has been directed to utilizing for man's comfort and convenience mainly solids and liquids. Only in compara tively recent times, however, has attention been seriously directed to the utilization of gases and to applying commercially the principle that solids and liquids may be reduced to gaseous forms, and so reduced find many fields of em ployment in the arts and sciences. It was as late as 1827 that the first commercial employ ment of gas was made in this country in which year illuminating gas was introduced in New York City. The next commercial use was in 1870 when carbonic acid gas was developed in dustrially. It is employed largely in carbonated beverages, fire extinguishers. insecticides and many other products.
In 1863 nitrous oxide was applied in dental operations for the purpose of permitting work without pain.
In 1875 oxygen was developed for medical purposes in diseases of the lungs. About the same time oxygen was employed in connection with calcium light for spotlights and scenic effects.
In 1895 acetylene was introduced commer cially to illuminate country homes and in bicycle headlights. About the same time anhydrous ammonia began to be used for refrigerating purposes.
In 1907 the manuracture of oxygen on a commercial scale for industrial purposes was commenced in this country by the liquid air process; and in connection with the industrial application of this gas, acetylene was used in welding and cutting steel with the oxy-acteylene blowpipe or torch.
Since 1907 many new gases, the existence of which in quantities in the earth or in sub stances known on the earth was unsuspected, have been discovered and put to commercial use. For example, it was supposed until recent
years that the air which we breath was com posed of four parts of nitrogen and one part of oxygen. It is now known that in addition to these two gases which make up the major portion of our atmosphere, there are eight other gases contained in minute quantities in it, among them, argon, neon and krypton. Of these gases, argon and neon have been found to have a commercial value, the former in the manu facture of incandescent lamps and the latter for lighting purposes. In like manner, helium, a gas which was known to exist in the sun but which was supposed to be a rare element on the earth, is now known to exist in many sub stances and since the declaration by the United States of a state of war with Germany, methods have been found for extracting this gas in large quantities from various substances at com paratively small cost. This gas is now being employed extensively for military ballooning, because it is not inflammable.
Within the last decade the discovery of new gases and the development of new uses for the known gases has brought into being a new industry which in the same period has grown with rapid strides until it has become an in dustry vital to the commercial life of the coun try and one which played an important part in the World War. As an example of this un precedented development, a single branch of that industry, namely, the oxygen business, may be taken. In 1907 there existed in this country a single plant which had been built in that year and which produced annually 24,000,000 cubic feet of oxygen. At the date of this article, some 12 years later, the yearly production of oxygen is estimated at over a billion cubic feet and the oxygen plants scattered throughout the entire expanse of the United States number over 200. The commercial utilization of the other liquefied or compressed gases has par alleled that of oxygen and to-day the United States is dotted with plants manufacturing com mercial gases representing an investment of well over $100,000,000 and an annual production of billions of cubic feet of gas. Despite all this the present stage of development represents the merest scratch of the surface of an immense field yet untouched which lies beneath for exploitation.