from the beginning of time each passing age has left behind some vital knowledge that has helped make this world of ours a better place in which to live knowledge that has made possible the countless conveniences we all enjoy today we look  our natural right to take them for granted and once having used them give no thought to days gone by when people did without even the simplest of all these hard won benefit yet nothing in today's wonderful world has come to  from the sun every development has been advanced a relentless never ending struggle for improvement transportation has sprouted wings to whiskas over the span of a continent in the space of a few pleasant hours today the iron horse travels faster and smoother in lighter streamlined ball boys by water now provides all the comforts of home in huge with the luxury liner the automobile has come of age offering speed safety ease and dependability under eames of only a few short years ago communication has made equal strides improving its earlier model and developing newer miracles like radio and television that add to our pleasure and welfare in the world of industry modern machinery of life and man's labor lifts giant burdens far beyond mere muscle please hand and i still greater scale imprecision yet today as for ages past the constant search for improvement continue or time is the greatest factor of all true progress time and its ever increasing heritage of knowledge and in this march of civilization one great force has steadily contributed more and more to our material welfare today and for the years to come the world looks for better things for better living through chemistry the science that has played a major part in the perfection of practically everything we  has carried us beyond the machine age on into a world of new materials that are not found in nature and throughout the entire chemical industry no name more honored than you upon contributor of many products that make life more secure more beautiful more livable among others products like vehicle was glistening durable beauty of finish compliments the mechanical perfection of modern motor car you neoprene manmade rubber that fills many uses beyond the ability of nature's own product you're pondering on that makes life more luxurious more beautiful or everybody everywhere ray on back by more than properties depend on how we each fabric is made its construction dying and other finishing operations as well as the quality of the our new the fact that ray on yarn successfully meets the requirements of textile makers and users is one great its rapid growth and wide acceptance within the space of comparatively few years hundreds of millions of pounds of yarn are required each year to meet the ever growing demand for a on fab day right on brings new beauty civilized world a product of test tube and retaught it is obvious that better ayaan means better chemistry right on by dupont enjoys a heritage of leadership unsurpassed in the chemical industry right on by twisted or laid together we have a yarn which may be woven knitted before formed in other ways into fabrics like all other textile fibers braylon has its own individual qualities and properties since it is man made under scientifically controlled conditions it is the most uniform of all text the fiber and can be varied to great advantage in its construction for example right on celebrants are continuous can be produced in great lengths and may be made finer fiber you plant was the first company to make rail and staple fiber on a commercial scale in the united states the use of re on staples has increased tremendously in the past few years largely because of the new and unusual fabric effect made usually the ranges from thirteen to two hundred seventy for example here are five specimens of re on yarn all the same size yet notice the wide variation the number of filaments contained in each sample number the arms provide fabrics and a wider range of weights and textures than those of any other textile fiber because of this post control of uniformity in the size and number of filaments desired another great advantages that  versatility reaches new and unusual heights when the need arose for a on yarn with special characteristics not then possessed by any other a on your bond developed a yarn to meet the need cardio are the core jewels in making automobile tires demand exceptionally high strength as well as resistance to keep and flexing card your a re on yarn fills these requirements so well that large quantities are used annually both and truck tires and tires for fas its strength and uniformity have also brought about its use in the sales of racing yachts and for other purposes and which on usual properties are required in the manufacture of iran there are three different methods generally you  best goes process the cellulose as a faith process and the cupra monium process it is important to bear in mind that yarns are made by all these processes are rail while each has its own different characteristics generally speaking entirely of this cause process right on others and tireless acetate right on the two types of yarn are also combined to make many distinctive fabrics with pleasing color effects and designs for example this piece of on diet white cloth is made entirely of this cause process right on and here is a diet particularly suited to the fabric i the table when properly dyed the cloth colors completely and even lay a solid color this piece diet white cloth is made entirely of acetate rail and when properly treated with the diet shown in this flask it too takes on a beautiful even solid tint as the dyed sample reveals the piece of on die a white cloth in the center is made of both yarn when the two diaries are mixed and the cloth is dipped into the combination dye a bath and interesting to color pattern is the result the best course process yarn takes on color from the diet for which it has an affinity and the a constituent in all plant life if we examine a tiny cross section of vegetable matter under the microscope we see a series of minute chambers or cells joined together by a binding substance the walls of these cells are made  which must be a pain in a very pure state before it is suitable for making rail that means all other materials have to be carefully and thoroughly removed in finely equipped laboratories each lot of  analyzed by a series of thorough chemical tests the highest standards a rigidly maintained and none but the best cellulose gets by these exacting technicians the extreme degree of scale and care employed here ensures after a proper amount of time the cellulose is squeezed to remove excess liquid the soft moist part of the remains is known as alkali cellulose next the material is thoroughly torn up into crumbs which must be aged for many hours during which chemical changes take place then the addition of a liquid called carbon by sulfide causes another chemical change the batch shrinks in volume to about half its original size its color gradually changes t brilliant orange which gives this step its name sensation when the orange colored crumbs are dissolved in water containing a small amount of sodium hydroxide the result is a syrup a liquid much like honey and appearance and flow called biscoe solution this is the spending solution so far we have seen nothing that looks like a textile fiber but when we drop a slender stream of the spinning solution into a hardening bath notice what happens it c solution is exposed to the action of warm air the acetone evaporates leaving a solidified substance a crude form of cellulose acetate ray on which as its name implies is a chemical compound wiley's rough demonstrations reveal the basic steps of the two processes and their differences actual manufacture is a complicated and elaborate development of these apparently simple steps every operation must be precisely controlled extremely fine limits of time and temperature or must be maintained every ingredient used must be of high purity proportions must be exactly calculated when we consider that every detail must be carried out with a laboratory precision it becomes obvious that only a great chemical organization can produce huge quantities of rain on yarns of