Chemicals And Dyestuffs
( Originally Published 1918 )
The practical value of chemistry. Chemistry has come to occupy an exceedingly practical place in modern industry. As a matter of fact, from the time he learned to make fire, man has always practiced the chemical arts ; the metallic processes are chemical at bottom, and so are those of agriculture. But these were carried on, in their earliest stages at least, without any understanding of their nature and certainly without any scientific insight or equipment.
Elaboration of products. It remains true, however, that products which require a good deal of working on them seldom, if ever, reach the stage for final consumption without having been subjected to some chemical process. This is a matter of common knowledge, although it is sometimes overlooked. Every metal must be refined ; fibers must be bleached, purified, and dyed ; leather, rubber, soap, and various kinds of food products must be preserved ; the materials of buildings, ships, and cars must be protected from the weather ; articles such as salt and sugar must be purified ; sand and clay must be treated before they can be converted into various manufactured objects. But none of these things can be accomplished by mechanical means alone ; chemistry is called on to participate in all such processes. The very earliest conquests of man over nature lay in the development of chemical processes of a simple order — in fact, it might be said that the fundamental invention of all, that is, fire-making, was a chemical one. It has been said that to deprive industry of chemistry would be like removing gravitation from the universe. The result would be chaos.
Sulphuric acid. The manufacture of chemicals in this country started in 1793, when sulphuric acid, the most important manufactured substance used in the chemical industry, was made in Philadelphia by John Harrison. Harrison made lead paint also, and while his enterprise was very small in its beginnings, it proved profitable, and soon his plant was expanded until it reached a capacity of nearly half a million pounds of sulphuric acid annually. It is said of this acid that it is a chemical barometer, and even that one can gauge the civilization of a people by the amount of sulphuric acid they use. In 1825 and later other concerns followed Harrison's beginning ; it is said that the Chemical National Bank in New York was established with funds derived largely from the manufacture of sulphuric acid. Various other acids are produced in the chemical industry : nitric acid was manufactured in Philadelphia as early as 1834, as was muriatic acid also; then there are " mixed acids " formed of nitric and sulphuric, which are used in nitrating organic substances such as glycerin and cellulose. Acetic, lactic, citric, and tartaric acids all have their importance in the industrial world, as well as in medicine.
Slow expansion of the industry. For many decades after our beginnings the chemical industry expanded slowly, for, as we have several times remarked, Americans seem to be cut out for mechanical invention of a practical and immediate utility rather than for that which requires more time and patience, as, for in-stance, laboratory experiment and study. Until the middle of the last century the most necessary chemical materials were manufactured in different Eastern cities on a small scale ; lead and zinc ,paints, various dyes, saleratus, and the acids were made, but the industry was relatively insignificant. The great development has been a matter of the last few decades ; much is being done now, and there is even greater promise, for our relations with Germany, the country which has led the world in chemical industries, became such that we were forced to turn our attention toward independence of her products, especially in the matter of chemicals and dyestuffs.
Sodium products. We have spoken of the acids. Another important chemical, with extensive uses, is sodium bicarbonate, which is used in making soap, glass, and other products. The process of manufacture goes by the name of Solvay. Common salt furnishes the sodium needed, so that the plants are often located in the neighborhood of salt deposits. Sodium bicarbonate occurs also in certain lakes in the eastern part of the country, the water of which, strongly charged with soda, can be evaporated to get the desired product.
Fertilizers. The production of artificial fertilizer is, perhaps, following the preparation of sulphuric acid, the next most important branch of the chemical industries. Among the essential plant foods are phosphorus, potassium, and nitrogen ; these are the three most vital foods, because they often exist in the soil in quantities too small for the needs of crops, so that the soil has to be strengthened by artificial means. Phosphorus is that plant food whose future supply involves the greatest concern. It is found in large quantities in various forms, such as in bones of animals, both recent and fossil. Phosphate rock is composed largely of such fossil remains of animal life, containing the phosphorus originally concentrated in the living bone ; such deposits are mined and treated chemically to produce fertilizer. By treating phosphate rock with sulphuric acid, what is called superphosphate is formed. The manufacture of artificial fertilizers in this country is recent, dating from about 185o, when some experiments were made in Baltimore, but the industry has continued to develop rapidly. There are large deposits of phosphate rock in Tennessee, Florida, and South Carolina, with probably much larger quantities of low-grade rock. In 1911 rock phosphate was discovered, in extensive deposits, in three different places in Montana. And we have found several other sources of phosphorus ; for instance, the basic process of iron and steel purification yields a by-product called Thomas slag, or basic slag, which is used quite extensively in England and Germany.
The use of fertilizers. Before going on with the other fertilizing elements, it is in place to recall what has been said before about the great natural resources which we once had in the soil. There were, not so long ago, regions in the Middle West which produced large yields without an ounce of fertilizer. It was only with the threatened exhaustion of the soil that we had to consider fertilizers at all, and this accounts for their late development here. The earliest form of fertilizing was the natural one of burning off the overgrowth and leaving the ashes ; later on the manure of cattle was used, and so were fish of the coarser and less palatable varieties. This habit of using fertilizer is one which people have to be forced to acquire ; and for many ages a people would abandon its lands and move on rather than go to the trouble of artificially restoring the soil. But when this art had been forced upon them, because they could not move on or for some other reason, they then began to study the characteristics of plants and of soils and to develop a science where formerly there had been at most a sort of chance success. In this country, with all the exuberance of soil and other favoring resources, we were naturally tardy in paying attention to these matters ; we went ahead and used up what there was, and only when the pinch began to come did we set our minds to the conservation of our resources.
Potash. Next to phosphorus the element of great significance among fertilizing agencies is potassium (potash). The great reserves of potassium deposits were long supposed to be con-fined to Germany; her deposits were thought extensive enough to meet the world's demands for many generations. But the Great War caused the rest of the world to set about the discovery of other deposits or other sources of supply. Extensive potash deposits have been found in the western part of our country, and they can be utilized commercially ; it had long been known that we had deposits in a number of localities, but their commercial importance was supposed to be slight. The manufacture of potash salts in the United States started in 1915, when a product worth over a third of a million dollars was shown. It seems that potassium is produced in some cases as a by-product from the manufacture of Portland cement in California. Potassium sulphate was made in Utah and Nebraska and placed on the market in 1915, and some of this desirable article was obtained from kelp cut on the Pacific coast. Thus it seems that a brand-new industry has been born among us ; in view of the importance, even the indispensability, of potassium, the commercial production of potash salts is a matter of considerable interest to the country.
Nitrogen. Until a few decades ago there was much concern among agricultural scientists as to the future supply of the plant food nitrogen. There are unlimited quantities of this element in the atmosphere, but plants cannot feed upon this free nitrogen ; it must first be converted into a nitrate. There are a good many sources from which nitrogen can be derived for the manufacture of fertilizer, but until recently the supply that could be produced was comparatively small. Waste parts of animals, dried fish, etc. were the source of nitrogen fertilizer; so-called fish factories existed along bodies of water such as Long Island Sound, and suffered more or less from legal proceedings instituted by shore-dwellers who objected to their odor. Then there are extensive deposits of sodium nitrate in Chile and farther north along the west coast of South America ; and there were formerly locations where guano was so thickly deposited as to be susceptible of mining. But nitrates are now manufactured freely as a result of the discovery that nitrogen by electrical methods can be combined with other substances so as to form nitrates. The advance of chemical and physical science has thus solved the nitrogen problem so far as agriculture is concerned.
The future of fertilizers. The increasing demand over the world for foodstuffs and the depletion of the fertility of the soil in most parts of the world by unscientific methods of farming are combining to call for more and more artificial fertilizer. It may be said that among future generations the demand for such means of keeping up the fertility of the soil will be as fundamental a demand as that for coal and iron ; chemical industries productive of fertilizers are likely, therefore, to have an important future.
Other chemical industries. There are a number of chemical articles produced by the aid of electricity ; in general, it is the consuming heat of the electric furnace which permits the melting of certain substances, for instance, calcium carbide, which in combination with water produces acetylene gas. Other branches of the chemical industry are the manufacture of oils and soaps, the latter being produced by the action on fats of some chemical like soda or potash. Coal tar is a by-product of the coal-gas industry, and under distillation yields oil, creosote, benzol, and other elements, and, especially, the coal-tar dyes, presently to be further considered. The value of our chemicals and allied products has expanded at a rapid pace within recent years.
The popularity of coloring. Dyestuffs have interested human beings since very remote times, for clothing and ornament have been colored by the use of vegetable and animal substances by most primitive races. Many tribes, to realize their ideals of beauty, have even tattooed the skin and colored the teeth and hair. One of the great motives in the development of trade in the Mediterranean by the Phoenicians was the value set upon the color purple, as seen in the Biblical expression " purple and fine linen " ; for, since the color was derived from a shellfish, the Phoenicians were led out upon the sea, and then farther and farther on, in quest of supplies of material. The human eye delights in color, and there will always be a steady demand for color-giving substances. The formerly common dyes were supposed to exist already formed in the plant or animal and so came to be known as " natural" dyestuffs ; among the more important of these are logwood, fustic (the heartwood of certain tropical trees), and indigo. The last is one of the oldest of dyestuffs ; in colonial times in America, when the manufacture of textiles was a household art, the indigo tub was as common a household article as the churn.
Beginnings of our dyestuffs manufacture. The actual manufacture of dyestuffs started in this country early in the last century ; there are records of dyes being made at Poughkeepsie, New York, in 1816, and in Philadelphia in 1834. At the present time they are made, in a very large proportion, from coal tar and so are a by-product of the coke oven. Coal-tar, or aniline, dyes were discovered about the middle of the last century, but there are now in existence upwards of 60,000 of these dyes. Among other things artificial indigo is now made from coal tar and has gone far to replace the natural dye. Until the outbreak of the Great War the bulk of the coal-tar industry was German, but since 1914 strenuous efforts have been made by various countries, including ours, to develop substantial dye industries of their own. Up to recent years this industry has been always relatively unimportant in our country ; in 1914 the production of synthetic dyestuffs amounted to something over 3000 tons, with a value of $3,000,000, and our importation of coal-tar dyestuffs was valued at over $900,000,000. Our domestic production consisted largely in the assembling into finished dyestuffs of semi-manufactured materials, but we have made a good many tons of aniline dye from benzol of domestic origin, this manufacture having started in 1910.
Effects of the Great War. When the Great War broke out in 1914, there was practically a cessation of coal-tar "intermediates " ; all that came from Germany, constituting about 86 per cent of our foreign supply, was cut off altogether. But many American industries are dependent upon the use of artificial colors, and the situation for them was serious in the extreme. American chemists and capitalists at once took up the problem of relieving the impending stress and of laying the foundation for an independent American coal-tar industry. The enterprise was a difficult one, for the industry had to be built up from the bottom, but within three years the problem was solved. Our variety of colors is still some-what limited, for a wide variety and perfection of quality can come only after a great deal of experience and experimentation. The German dye industry was the result of long years of chemical research and technical training, and we could not hope to duplicate its performances offhand. The situation drove us back once more to the natural dyestuffs, use of which relieved the first acute stages of the color shortage ; and we have also developed mineral dyes, such as chrome yellow.
Home production of dyes. The remarkable expansion of our dye industry since the summer of 1914 is one of the results of American initiative. We were making about 3300 short tons of dyes in 1914, but the output had increased to 15,000 in 1916, all out of American coal tar, and the industry has continued to expand. The national Bureau of Engraving and Printing, which produces all our paper money and postage stamps, managed to secure, early in the war, several shipments of dyes, which were used most sparingly and in diluted form ; certain of the postage stamps issued for a time thereafter were considerably paler than they were before the character of the dye was changed. It is safe to say that at the present time the bulk of the artificial dyes consumed in our industries is made in American plants, by American labor, from our own raw materials.