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INDUSTRIAL A N D ENGINEERING CHEMISTRY
VOl. 19. No. 10
Contributions of Chemical Science to the Communications Industry' By Clarence G. Stoll2 K'ESTERV
ELECTRIC CO , INC, KEw YORK,N. Y
0
U T of t h e d r e a m s of those prophets of the physical sciences who lived in the late eighteenth and early nineteenth centuries, men have built a mechanized social order, the reality and significance of which even we, the beneficiaries, do not fully comprehend. T h e y could not p o s s i b l y h a v e f o r e s e e n our e v e r y d a y conveniences which have resulted from their pioneeringefforts. It was impossible that they could conceive Clarence G. Stoll the modes of trans-' portation and communication of today. Nevertheless, they laid the foundations in their method of acquiring knowledge and putting it to work. In outlining what one division of physical science has contributed to modern communications, I must content myself with reciting a list of accomplishments, because I am not sufficiently conversant with chemical science to do more. I n confining my brief remarks to the contributions of one of the great divisions, I cannot draw sufficiently fine distinctions clearly to avoid the field of the other, and I sometimes wonder if the chemist and the physicist really wish or intend that it shall be possible. Foundations of the Communications Industry
Modern communications were perhaps the first fruits of the labors of Faraday and Maxwell. At any rate, the results of their labors found application contemporarily in communication and electrical power developments. What, then, chemistry has done for the one, it has done also for the other. Very early the experimenters with electrical energy found a source of such energy in chemical reactions, and a means of quantitative definition of this elusive force in the chemical reactions which it induced. It may seem elementary to mention the familiar primary cell, but its origin, as all chemists know, rested on the discoveries of Volta in the late eighteenth century. The discovery of the principle of the gravity cell is almost as old. Leclanch6 in 1868 made the first sal ammoniac cell which was the direct ancestor of the so-called dry cell of today. And it has not changed much in forty years. Before our Civil War, Plant6 had devised the secondary cell, or accumulator, based upon the electromotive forces potential in the several oxides of lead. Brush reduced these 1 Address before the Chicago Section of the American Chemical Society, June 24, 1927. 2 Vice president, director, and general manager of manufacture Of the Western Electric Co., Inc.
experiments to the commercial form of our common storage battery. If Plant6 could look into the battery room of the State-Central Telephone Exchange in Chicago today and see how his child has grown, his imagination might easily terrorize him. Because of the precision with which chemists can measure and predict reactions, the practical standard of electromotive force-the international volt-is still a form of primary cell, depending for its accuracy upon the certainty with which chemistry can reproduce materials of definite form and purity. Thus were the foundations of a communication industry laid in a few fundamental chemical reactions, which the chemists of eighty years ago measured with precision and adapted to curious devices with which t o experiment on that elusive form of energy. The story, from the early forties of last century, every school boy knows. Communication, first by code signals over a wire, and later by actual transmission of the voice, grasped the imaginations of many men. Wires were strung on poles, fences, trees, and buildings. An industry was born. Properties of materials to harness this new power were scrutinized, and because chemical science had gone far in determining those properties, commercial materials already in use in the other arts were available. The communication industry has used of them freely, first taking them as it found them, then asking for something better or different when it thought it knew what it wanted. Materials Used by Chemical Science
There are four groups of these materials and thiough them chemical science has probably made its greatest contribution to electrical communication: (1) Materials for conducting electrical forces ( 2 ) Materials for controlling magnetic forces
( 3 ) Materials of apparatus structures (4) Materials of electrical insulation
This order is not significant of relative importance or emphasis, but only an order in which I will treat of them. Knowing that a title or a name will quickly suggest to the imagination of the chemist the part which chemistry has had in the advent and utilization of these materials, I can scarcely do more than mention most of them. MATERIALSFOR CONDUCTINQ ELECTRICAL FORCES-of course, at the top of the list in the first class is copper, obtainable today by the communications industry in its high degree of purity and unifomity-thanks to the chemist who developed the now almost universal method of refining electrolytically. True, the needs of communications for a pure and uniform copper were not his sole motivation, but that is beside the point. Communications today rely upon a procession of opening and closing a veritable maze of electrical circuits. At each point, in a circuit where this is necessary, there must be a metal-contacting surface, which will reliably make and break contact. Platinum was early used, and it was comparatively cheap. Silver is a better conductor but its surface will not stay clean. Communications bulled t h e
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INDUSTRIAL AND ENGINEERING CHEMISTRY
market of platinum. It brought down on its head the maledictions of chemists because they had to lock up the laboratory crucibles in a safe. They had a real stake in the matter, so they found a series of alloys which have largely replaced platinum in communications and, what is more, in the last few years the old worn-out communications equipment, coming into the junk pile for salvage, has been a substantial source of platinum for crucibles and milady’s decorations. Solders are very necessary bonding agencies for electrical circuits. Although I doubt that chemistry originated them, it learned some things about them so that they can now be used more intelligently and economically. Chemical science gave us carbon in usable forms as conductors of electrical energy, especially the lamp filament (which, by the way, is still very useful in communication though not in illumination) and artificial graphite. Microphonic carbons we still use with slight improvements only over the coal which nature gave us. For high-resistance alloys that are durable and economical the communications industry is indebted to William Hoskins. hfATERIALS FOR CONTROLLINQ MaGNETIC FORCES-In the second group of materials there have been outstanding developments for the specific use of communications because the progress of the art very largely depends upon knowledge of and ability to harness magnetic forces. It is so long a story and the contributions of chemical science have been so interwoven with those of the electrical physicist and engineer that several books are needed to tell it all. I3ut here are the products listed approximately in the order of their appearance in the art: Pure iron for electromagnets Silicon steel for transformers Tungsten steel for permanent magnets Electrolytic iron. pure and finely powdered Iron-cobalt permanent magnets High permeability iron-nickel alloys High permeability iron-nickel-chromium alloys High permeability iron-nickel (finely powdered)
Of these, chemical science had developed for the other industries pure open-hearth iron, silicon steel, and tungsten steel. The others chemistry brought forth a t the call of communications. There has been an incorrect belief that the communications art adopted electrolytically refined iron to get a high degree of purity. We asked for a reasonably pure iron, which could be pulverized so that it could be molded into the desired core shapes. Quickly the chemist came back with an electrodeposited iron, hard as glass and more brittle. There are many interesting incidents in this episode reflecting credit on the science of chemistry. When the physicochemist came forward with those most astounding ironnickel alloys, which have more than quadrupled the speed of transoceanic cable communication, of course we asked, “Can you not give us the alloy in a brittle form in order that it can be finely powdered so we can adapt it for use on our land-lines equipment?” They did, with the result that the present-day Pupin loading-coil is no larger than rz doughnut. The chemist, every little while. springs something on us which revives the awe in which the ancient public held the alchemist. The chemist must not blame us if we demand of him that which now seems impossible. He has educated the wonder out of us, so we confidently expect to receive anything we request. LIBTERIALS O F APPARhTUS STRUCTURES-The apparatus structures required in communications, apart from electricand magnetic-conducting media, use mostly the partially fabricated materials of the other arts. TS’ood, iron, nonferrous alloys, aluminum, and lead comprise the frame works.
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The contributions of chemistry to the alloy steels have fallen proportionately to the benefit of communications development. Especially has the scientific improvement of the copper-zinc and copper-tin alloys contributed to the success of our industry. Essential to our structures are many kinds and shapes of rubbing and pressure contacts, where spring materials of high resistance to fatigue must provide the integrity of the circuit. Possibly these materials should have been discussed in the first group of conducting elements, but I place them in the structural group because their mechanical properties are more essential than their electrical. The work chemistry has done on resistance to corrosion, fatigue under stress, and uniformity of quality by control of primary manufacture, cold working, and heat treatment has given to our industry such superior alloys as the nickel silvers, phosphor-bronzes, duralumin, manganese and aluminum bronzes, and die-casting alloys. To help cut the costs of structures, the chemist has given us the brasses which can be machined at high speeds, yielding surfaces which need no subsequent finishing operations; also brasses which can be hot-pressed to intricate shapes. The communication industry chose lead as a protective material for its cables because it so effectively resists the ravages of time and weather and is so soft that it can be pressed on the cables, effectively sealing out moisture. Its mechanical weakness has been our big problem, to the solution of which the chemist has made substantial contributions in fundamental knowledge of lead alloys. In our conduit structures, through which the wires of communication are fanned out under the great metropolitan areas, we have used wood, preserved and unpreserved, stoneware conduits, metallic pipes, and sometimes nothing but the bare lead sheath. hI.%TERIALS O F ELECTRICAL hiSvLATIos--When chemists say that a substance is insoluble in a given solvent, I am told that they do so with certain mental reservations well understood among themselves. Apparently, the electrical physicist makes similar reservations when he says that a medium is non-conducting for electrical energy. I n dealing with the distribution of electrical energy for power uses, the designer of plant looks for insulating media which will withstand without rupture the potentials imposed upon them. He has less concern for the energy losses and distortions which occur through the insulations. Communications, dealing relatively with minute quantities of energy and with high frequency currents, is vitally concerned with both direct energy losses, through the insulation and distortion of the form of oscillatory current so essential to the integrity of signals, and the fidelity of voice reproduction. The early experimenters in the field seized upon the handiest commercial materials which the electrical physicist declared to be non-conducting. These were frequently what I believe the chemist calls organic compounds or derivatives, products of nature, sometimes products of synthesis in the chemical laboratories. They are: textiles (cotton. silk, wool) ; plastics (rubber, natural resins, synthetic resins, bitumens) ; natural oils (fats, hydrocarbons) ; natural waxes; synthetic waxes; japans and organic enamels; cellulose derivatives; papers; and wood. I n the inorganic group, communications early seized upon ceramics, especially glass, vitreous enamels, and porcelains. We, outside chemical science, feel that a real measure of success in the inorganic group awaits an application of effort on the part of the chemist that is comparable with the effort he has applied t o the organic group. I n the insulations group, communications were restricted to relatively simple fabrications of natural products. But when they called for materials particularly adapted to its
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I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
purpose, chemistry responded nobly. The chemist has lifted the manufacture of paper out of the traditions of craftsmanship. Chemical science has learned much about the reactions of the fibers, so that it has given to the electrical industry a dielectric material which fulfils a very definite need. The chemist has produced for communications organic enamels which can be applied to conductors, giving sufficient isolation and thereby sufficient insulation, and permitting large economies of space. The value of this contribution to the communication industry alone is represented by a sum running into eight figures. Insulating and decorative enamels made from derivatives of cellulose in which the organic chemist has made tremendous strides are finding expanding usefulness in communications. One of the greatest single contributions to the insulations problem of electrical communications has been the synthetic indurating resin. It marks a real episode in communications apparatus design. By means of it, whole assemblies of complex conducting units can be integrated with their necessary insulations in one stroke of a machine. It means more durable structures, smaller units, enhanced appearance, lower costs. The names of Baekeland, Redman, and Aylesworth will forever be associated with this contribution. Chemical Control of Materials
Uncovering fundamental truths by which materials are adapted to the various needs of the communication business, is not all the chemist has done. By the diligence, patience, and skill of chemists, means of control of the essential characteristics of these materials have been so precisely defined that the industry proceeds with confidence in the performance of its public function. With the chemical laboratory standing guard a t the raw material gateway, we are not afraid. We know that chemical science has realized a high degree of precision. We also know that when the chemist must guess, he tells us SO, and tells us how much he thinks his guess is worth. I have refrained thus far from reference to that part of the industry with which I am identified. The ideals of accuracy which chemical science has established so dominate the service of the chemists associated with us that our confidence and the confidence of our raw material supplies has made it possible greatly to reduce the amount of routine laboratory inspection and the attendant cost. This has released facilities and talent for the more interesting work of control of our own manufacturing processes. To the usefulness of that sort of control in the manufacture of communications equipment I cannot omit a tribute. Without it, what one group of chemists has contributed to the development of a magnetic alloy might easily be lost in the process of manufacture, The facts of electrolytic deposition of metals would be largely overlooked in routine production; the principles established for optimum quality of japan and lacquer finishes would be neglected; the proper mixtures of earths for porcelains, glasses, and vitreous enamels would not be observed; carbon electrodes would come out of the factory in irregular quality; insulating papers would so vary in those specific qualities which the science has laboriously developed that they would fail to perform their functions; metallic and other chemical finishes would fail to protect; working conditions in chemical processes would become intolerable to the comfort and health of workmen. So within its own manufacturing units and those of its suppliers of raw material, somewhere a chemist stands guard, that universal communications may not fail. RECLAMATION OF WASTEPRODUCTS-It would be interesting, if there were time, to tell what the chemist is doing
Vol. 19, No. 10
in the reclamation of waste products of the communications industry. Through his development work and his control the metal value of its worn out and obsolescent structures is recovered to be put quickly to work again in new e q u i p ment, Thousands of tons of copper and lead and their alloys are reclaimed annually. In one special laboratory in our particular industry, several hundred thousand dollars’ worth of precious metals are reclaimed every year. PROTECTION OF STRUCTURES-In discussing the chemist’s contributions to manufacturing control, the importance of Drotection of its structures cannot be overlooked. The list is too long for spec& treatment, but an enumeration of the items will serve as a reminder. Not the least in importance is the protection of wood from decay. As R result of chemical science, today ninety per cent of the poles for communications lines in the United States are treated with preservatives before installation, which conservatively means an increase in useful life of more than one hundred per cent. For the dual purposes of protection and appearance of apparatus structures, all of the following protectives and protective processes are used: drying oil paints; oleoresin varnishes; bituminous paints; japan; cellulose and gum lacquers; artificial resin varnishes and lacquers; electrodeposited nickel (zinc, copper, tin, cadmium, gold, and silver) ; sherardizing; hot galvanizing; hot-dipped tin; iron phosphate coatings; vitreous enamels; and iron magnetic oxide coatings. In many of these processes, the chemist has risen to the call of the industry to make improvements not heretofore demanded by other industries. Particularly is this true of the iron-magnetic oxides, where, by application of chemical research methods, the chemist has produced a finish for iron and steel which is so superior to the old Bower-Barff process that it is hardly just to continue to identify the process with the name of the original inventors. Television
I wish I were able to expand upon the contribution of chemical science to that newest offspring of communicationstelevision. Certain it is that without the knowledge of photoelectric phenomena which chemical science has produced, that most astounding artificial eye, the photo-electric cell, would not be a reality. Future PGoblems for the Chemist
I cannot conclude this subject without a reminder that the work of the chemist for communications is not only unfinished, but is just beginning. Permit me, then, to make just a few suggestions. Most of the contributions of chemistry to communications have been made under the stimulus supplied by other human needs, but when communications specifically called to the chemist for new knowledge he did not fail to answer. Therefore, her future calls may be the more imperious. She will expect new and improved properties for metals and metallic alloys by virtue of the expanding knowledge of subatomic phenomena. How about higher conductivity alloys? Communications needs a cheaper and better mechanical protection for its “nervous” system than lead and its known alloys now afford. We believe t h a t textiles, as now offered, do not present the best insulating qualities of which they are capable. Specifically, we have needed for a long time an insulating medium for condensers which possesses a higher specific inductive capacity without sacrifice of insulating value. How about a secondary cell that is lighter, cheaper, and longer lived? The earth’s crust is abundantly furnished with the compounds
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INDUSTRIAL A N D ENGINEERING CHEMISTRY
October, 1927
of aluminum and magnesium. We hope for the development of new properties of strength and durability for these metals and their alloys. We shall keep after the chemist until he produces a fibrous or plastic insula%ng medium with less energy -dissipation. The chemist has raised our hopes about a waterproof and fireproof insulation, thin and effective for small conductors. We shall keep on demanding something better. We confidently believe that, with the chemists' knowledge of carbon compounds, he will some day doctor-up the rubber or resinous hydrocarbons t o give us a better material than guttapercha for deep sea cables. Remember, it must not absorb water, nor deteriorate under high hydrostatic pressures in salt water. While the chemist is on this problem, he must not forget
that the rubber hydrocarbon is still too sensitive and temperamental t o endure the service we would like t o subject it to in our present structures. We invite the chemist t o think about the need for a nonpoisonous neutral or alkaline substance t o replace cyanides in electroplating processes. We would like t o have a silver or cheaper contact metal or alloy which will not corrode or freeze under the contact spark.
These are only a few of our demands; the future will bring more. Just yesterday the chemist jimmied the atom, and we confidently expect it has something in store for the communications industry--we will look to chemical science for it.
Effect of Ethylene on the Composition and Color
of Fruits'
By E. M. Chace and C. G . Church LABORATORY O F
FREITA N D
VEGETABLE CHEMISTRY,
u. s. BUREAUOF CHEMISTRY A N D SOILS, LOS ANGELBS,
CALIF.
The ethylene method for coloring citrus fruits was create an atmosphere containHILE F. E. Denny patented by F. E. Denny in 1923. At that time and ing about 1 part of the gas in was working out subsequently an investigation of the effect of ethylene 5000 parts of air. The gas the details of his on the composition of citrus fruits was made and little charge was given twice each method for accelerating the or no change was noted. The effect of propylene on the day, The fruit was ventilated coloration of citrus fruits with color of lemons was tested and other fruits including for at least an hour each day. ethylene a t this laboratory in persimmons, dates, tomatoes, bananas, and avocados From 2 to 5 days were re1922 and 1923, other members were treated with ethylene and its effect on the color quired for coloring. of the staff were attempting and texture carefully noted. The methods used for analto reveal any differences in ysis were those of the Associacomposition produced by the ethylene treatment. Since Doctor Denny's separation from tion of Official Agricultural Chemiska The results are given the laboratory, work on coloring avocados, bananas, dates, per- in Table I. No material difference in composition between simmons, and tomatoes has beenundertaken. As the timethat the treated and untreated fruits is revealed. If the sigcould be spared for these experiments has been limited, the niiicance of the differences shown is calculated according to results have been fragmentary, and to the writers, incon- Student's formula,' it will be found that the odds are less clusive. However, owing to the wide publicity given to the than 2 to 1 that there is a difference in composition between alleged ripening effect that the process is said to produce, it the treated and untreated lots. There is no indication of seems advisable to publish at this time the data resulting from any change in composition where it might be expectedthis work rather than to wait for an opportunity to complete namely, in the sucrose and acidity. With the sucrose the means are the same; with the acidity the odds are but 1.8 the project. to 1 that there is any difference. Oranges and Lemons The results of the analysis of several samples of peel are The study of oranges and lemons was begun in 1923 after given in Table 11. Again no striking difference in composiDoctor Denny had proved the effect of ethylene on the color tion is indicated. of citrus fruits.2 Samples were secured from commercial Another group of samples was used in 1923 toshow the lots of fruit in packing houses, before and after the lots had effect of storage, ethylene treatment, and sweating by means been colored by ethylene. The check sample was taken from of stove gas on the sugars and pentosans of the peel. The several field boxes before they were treated witkithe gas, and composition of these samples is shown in Table 111. The was held at the packing house at air temperature until the orange sample was, divided into three lots. The first was main lot was colored. The same field boxes were again sampled, and both samples were placed in cool storage until analyzed a t once, the second was stored a t room temperature, analyzed. It would have been better to have kept the check and the third was treated with ethylene. The lemon sample samples at the same temperature as that to which the fruit was treated in the same way, except that it was colored by placing in a room where a kerosene stove was burning. Each was submitted while being colored, but facilities for doing set of samples was divided into three parts for analysis in this were not available a t the packing houses without great order to observe the variation. The results show no marked risk of coming in contact with air contaminated with traces or general trend. of ethylene or stove gas. Samples of from eleven to Efty In 1925 two sets of lemon samples of ten fruits each were fruits were evenly matched for color and size. Although the methods of treatment were not identical in all cases, the treat,ed with ethylene and propylene a t room temperature. same general procedure was followed in each packing house. The results are shown in Table IV. Time could not be alThis consisted in placing the fruit in tight rooms or under lowed for further tests, but ethylene in a concentration of canvas and forcing into the enclosure sufficient ethylene to 1 to 100,000 seems to be a much more effective coloring agent than propylene in a concentration of 1 to 5000. 1 Received July 25, 1927. * Chace and Denny, THISJOURNAL, 16, 339 (1924); Denny, Bot. Gas., * Assoc. Official Agr. Chem., Methods, p. 89, 88; p. 120, 24; p. 192,
W
17, 322 (1924); J . Agr. Research, 87, 757 (1924); U. S. Patent 1,475,938; Uficial GUE U.S. Patent O f i c e , 817, 82 (1923).
89; p. 210, 6; p. 213, 16 (1925). Love and Brunson, J . Am. Sot. Agron., 16, 60 (1924).
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