brought about another interesting development in this industry. Toluol, which is used extensively in making explosives, is one of the ingredients of illuminating gas, and during the war a number of plants were erected in Anerican cities for its recovery. The removal of the touol from the gas, however, depreciates its light-giving pover when used in the ordinary open-flame gas burners, but it does not materially decrease its usefulness when the incandescent gas mantles are used. This situation has led to an increased demand for the production of maniles, and has had a stimulating influence on this industry as well as on the industry producing thorium nitrate.

Some of the new industrial developments in the United States during the war will not survive the postwar competition. National interests do not require the degree of self-sufficiency that the war has compelled in some lines. It would mean unnecessarily high prices and even hardship on consuming interests. There will be a readjustment when the international trade returns to normal which will eliminate some American producers.

Industrial isolation is not a wholesome condition. But neither is complete industrial dependence upon a foreign industry, occupying a monopolistic position, a wholesome condition. The war has demonstrated how essential it is to national interests to have within our Nation industries that produce those materials and articles necessary to military operations and to the operation of the great industries of the United States. Adam Smith says that "defence is of much more importance than opulence," and today an efficient defensive organization includes not only armies and navies,

but also the great essential industries. We hope for the ending of war, but it would be folly for a nation to refuse to plan for its own safety, particularly until international government has approached closer to perfection. The war developments in American industry are not disposed of by saying that if they cannot compete with their foreign competitors, they must be eiiminated. National welfare may require their preservation and may make it desirable even at a price. A careful survey should be made to determine the essential or "key" industries, and tariffs, subsidies, or other aids, if necessary, should be granted in order that the percentage of these products necessary for national well-being shall in the future be produced in the United States.

CHAPTER IV

THE CHEMICAL INDUSTRIES: II, UNDER THE WAR DEMAND

Demand for war supplies a second major influence modifying the chemical industries. - Chlorine in the manufacture of poisonous gas Effect of stimulating its production - Caustic soda and soda ash-Sulphuric acid-Sulphur resources of the United States-The war and Chile's monopoly of nitrate of toda Nitric acid from synthetic ammonia- Smokeless powder - T. N. T. — Picric acid — Relationship between explosives and dye industry-Varnishing airplane wings — Var uses of acetone - Antimony - Quicksilver - Importance of chemical industries.

The demand for chemicals and chemical products in modern warfare was a second major influence on the chemical industries of America. Its influence was not revolutionary, however, until after the United States declared war in April, 1917. By that time, as has been pointed out, many fundamental changes had been caused by the curtailment of imports from Central Europe. War orders arrested some of the new developments and started some radical changes. It is interesting to consider how different the course of the American chemical industry is today from what it probably would have been had we remained neutral.

The influence has been far-reaching, not only because chemistry has played such a vital part in modern warfare, but because the chemical industries are so interrelated that an effect on one is felt in many others. The demand for chlorine in the manufacture of poisonous gas is a case in point. The part that chlorine plays in the manufacture of poisonous gas is analogous to the

part played by nitric acid in the manufacture of explosives. The three important poison gases are chlorine itself, phosgene, and mustard gas. Both phosgene and mustard gas are compounds of chlorine and require free chlorine in their manufacture.

The electrolysis of a solution of common salt yields caustic soda and chlorine in chemically equivalent amounts. But in normal times the market demand for the former far exceeds the demand for the latter, and because the chlorine is dangerous to life and destroys vegetation, it cannot be permitted to escape into the air. Hence, the production by this process of caustic soda, so necessary in soap making, paper manufacture, mercerizing cotton, and the purification of mineral oils, is limited by the amount of chlorine products that can be sold. As a result, there has been a tendency to overproduce chlorine in order to obtain more caustic soda. The chief peace-time use of chlorine was in making, in combination with lime, bleaching powder used extensively in textile and paper mills. The home production in 1914 was 155,190 tons, and the importation, chiefly from Great Britain, was 23,712 tons. Normally it was sold at very low prices, in the neighborhood of two cents per pound. As the production of caustic soda from salt by electrolysis was limited by the market for chlorine products, the deficit was manufactured from soda ash.

Into this complex interrelationship the war brought many modifying factors. Immense quantities of chlorine were required, and a rapid expansion in productive capacity occurred in this country and abroad. It is probable that at the end of 1918 the productive capacity in this country was four times as great as it was in 1914, and large additional plants were being erected when the armistice was signed. The production of

caustic soda has also increased, but not to the same degree as chlorine. Caustic soda, in addition to its important peace uses, is an essential in making explosives, particularly picric acid.

Acute competition in chlorine and chlorine products is certain to arise with the disappearance of the war demand. Peace uses probably cannot be found for the increased production, and some of the new plants will have to shut down. International competition in bleaching powder is certain to present an important problem for consideration.

A word should be added about soda ash for with the exception of sulphuric acid it is commercially the most important chemical substance. It is an essential in making explosives and is also used in the manufacture of glass, soap, wood pulp and paper, and many other products. Great Britain has for many years been an important producer. Her development in this industry began when the Leblanc soda process was the method of production. Later, while retaining the old process in some factories, she developed on a large scale the new and more efficient Solvay process. In 1881 the Solvay process was introduced into the United States and beeame the basis of the American soda-ash industry.

Many complicated engineering problems have arisen and have been successfully solved. Recovery of byproducts has reduced the cost. The process is continuous; raw materials are fed in at one end of the large, complex plant and the products are turned out in a steady stream at the other. The large towers in which the main reactions take place are often more than 100 feet high. The Solvay process uses much less fuel and labor than the Leblanc process. Labor-saving machinery has been perfected. With a low labor cost and