look for great advancement in all industry t.liruiigh cooperation with tlie cliemical industry. But, someone may object, the relation of chemical industry t,hrougli the factor of cheniicxi research and development is a competitive as well as a cooperative one. Syntlictic indigo displaced natural indigo; syntiietic methanol shows a tendency to displace more or less completely alcohol produced by tlie destructive distillation of hardwoods; ryntiietic motor fuels produced by the hydrogenation of coal might displace motor fuels produced by t.he distillation and cracking of oil; synthetic rubber might displace natural rubber. Tlie answer tu this inquiry lies in the mrkiiig of fundamental ecorioniic Ia7~. Ii a new product is as well adapted as an old one to the piirpme to he served and cheaper, or if the new product, wiiich nray be developed, inlfils requirements iiot heretofore met by eristisig products, it must find its place in industry. It should be recognized, liowcver, that in by far tlie large majority of cases tiie development of new products sewes nnly to supplement existing needs and serves for tlie basis of ~shollynew industries hecause they enlarge man's control over his crivironment. Where a riew product displaces an old
product, it is either fundarucntally clieaper or better, or very often both. The manufacturing processes of the chemical industry deal primarily with the transformatk~aof matter. It is to be expected, then, that the consistent and comprehensive research work of the chemical industry will deT7elop products new in their chemk:al make-up from time to time. Arid these new products are bound to have aii important relationship to other indust.rirs. In other umds, as cliciuical industry progresses, so rrill the industries which it serve8 progressand it serves practically every industry.
( 1 ) 'ln"D,mou9, Che,"'. e ' 31e.1. RW., 35, :i (1928). (2) Norton. T.H . , J. ISD E m CHEX,.8 , 1039 :I!?lij) (3) Partridge, Z. P . , lhid., 24, 8'35 (1'332) (4) U. 8. Cenais of Mnimfneturcs, 1914. (6) Ibid.. 1931. S~BCFIIIEU Maroh 24, 1033. Prcsrntsd b i w e tibe goriornl r n e e ~ i r i ea i the 88th Meeting of Uie Ameiicsn Cherniunl Sorietv, Tashington. D. C.. \$arch 27 i o 31, 1933.
ChemistryIts Interrelations with Other Sciences HUGHS. TAYLOR Princeton University, Princeton, N. J. X THE ancient "University"
of Alexandria the different facult,ies of learning, ma.thematics, astronomy, rnedici~ie,elieniistry, aad tlie like were lodged, in descending order of merit, at various levels in tlie building. Chemistry was in the basement. Two thousand and more years have pamed, with bewildering fluctuatioris in tho esteem and respect assigned t,o the various sciences. They have parted along diverxent paths to rea p p r o a c h and intertwine. They have ~nultipliedand subdivided. Today, we may liken tiie domains of science to B vast isic.omplete jig-saw puzzle of nature, each domain partially developed, each still requiring much engrossirig labor before a satisfactory u+iole may he exhibited; all, howewr, are interdependent and necessary units in the presentation of the phenomcna of nature i ~ sa whole.
I
11Ek.4TIOS 03- CITEMlSl'RY TO
Asmoi\.onru
It would have been difficult for the astronomer in tiie upper levels of the Egyptiau seat of learning to have visioned his colleague in the basement as the representative of the science which, ultimately, u-ould bring to astronomy the apparatus and methods vvliereln tlie intimate details of the outer tars would be revealed-their composition, their atniospheres, yea, even tlie very motions of tlie various universes beyond ours. Bunsen, perfecting liis mcthods of spectrum asialysis could never, eren in his most extravagant momcnts oi enthusiasm, have imagined all the towering array of astronomiea1 data that Iris instrument T%-ouidachieve uitliiii a century. The catalog oi the atomic constit,nents of the solar 6ystems could have been foreseen. The spectra of stripped atoms; the brilliant deductions based on clieniical thermodynamics
by SaBa, Russell, Mihe, aiid others, on spectra and btellar temperatures; the atmospheres of the planets deduced from the absorption spectra of molecules; and latterly the reti sliift of the spectral lines froin the nebultr, wit.11 its relativistic bearings and its revolutionary conclusions due to Leniaitre concerning the expanding universethese are derivatives of the developniont of spectroscopy by Buiisen and Kireihoff at which even today we can only manrel.
RELATION TO MAT HE MA TIC^ Innumerably, in the long history of the science, the chemist lias been invited to perfect himself in tlie realms of matheinatical science. As early as 1000 A. I). an Arabic alcliernist recommended that the aspirant to sueli knowledge of the science of cheniist,ry as then uas known sliould undergo a mathematical training by reading Euclid and the Almagest of Ptoleniy. Today, in the era of n.ave mechanics, the requirements are more severe. Geometry and trigonometry must be supplemented hy tiie elements of calculus, diiferential equations, and tbe theory ol prorobahility in order that even the easy reaches of pliysical chemistry may be understandingly explored. And lie nlio mnild t,ravel farther to the outermost frontiors of knowledge must cont,emplato submission tu tlie discipline of Namili.onian and Jqrangian eouations. of Hermitian arid 1,csendre _ nolvnomiais. of " matrices, and group theory. Tliere are, in Americacqecially, still too many u.ho object to this intrusion of ma,themiaticsinto chemistry, and tl!erc arc also too many bright students of the science who are liaiiipered, during those years when tlie acquisition of such kliouledge is relatidy easy, hy the conservatism, if not tlie iirnorirncc, of their teachers in such matters. Many of tlic popular elementary texts in pliysical chemistry cater to s:ieii deficiericies in the iristructional staff and mey be regardoti as insulting to the matliematical
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INDUSTRIAL AND ENGINEERING CHEMISTRY
capacity of the taught. That the time is now ripe for a change both of heart and of mind among teachers of chemistry is evident from the recent brilliant applications of mathematical physics in the realm both of equilibria and of reactioll kinetics. Statistical mechanics in the field of entropy and specific heats is reaching out to conclusions which are beyond the reach of present experimental technic. KO one who understands can fail to realize the paucity of our knowledge-for example, concerning elementary hydrogen, before the development of symmetrical and antisymmetrical eigenfunctions. The most striking recent developments in the theoretical treatment of reaction velocity, of valency, of isotope separations based on reaction rates, of the concepts of steric hindrance, of conjugated linkages, of the stability of the benzene ring, of the manner and mode of substitution therein, are developments for which the unavoidable preliminaries are advanced excursions into the realm of higher mathematics. Every science develops under the spur of the service rvhich it may render to another science. Just as a service to medicine was the inspiration to further chemical effort in the Iatrochemical era, so today a realization of the fertility of advanced mathematical technic in physics and chemistry is an added inducement to the mathematician to pursue his studies still farther. An eminent mathematician a t Princeton recently remarked that the striking progress in modern physics and physical chemistry had arisen from inquiries as to the data which specific mathematical tools could be made to yield when applied to physics and chemistry. Perhaps, he added, the next great developments may come from the application, for example, of analysis situs to physical problems. As yet, no one can foresee the contact. Time alone can show.
RELATION TO PHYSICS It is remarkable how many of the chemist’s objectives have, in the last twenty-five or thirty years, passed into the field of physical research. Transmutation, the lure of the alchemist, is now a problem in process of solution in the physical laboratories of the world. iltomic energy threatens the whole structure, built in the nineteenth century upon the basis of chemical reaction energy. Problems of structure and binding energy are other major physical concerns. Problems of valence are being rapidly reduced to mathematical-physical calculations involving wave-mechanical concepts. This is the more remarkable because so many of the fundamentals upon which these advances have been built are largesse from the chemist’s pioneer work. KO one can deny the electrochemical bases upon which the electronic structure of elementary matter was built. “Structural organic chemistry,” as G. N. Lewis points out, “although developed without mathematics, except of the most elementary sort, is one of the very greatest of scientific principles.” But the more penetrating analysis of that field is now largely in the hands of the physicist. Radioactivity, a chemist’s discovery, while it has contributed some small share to the development of our ideas concerning reaction mechanism, has become one of the most potent instruments of physical research. There is room for emulation, among modern chemists, of the aggressive and enterprising activity of the modern physicist. Too often our attitude is but passive. We are content to admire from a distance those epoch-making advances which not only are revolutionizing the sciences but also the whole structure of philosophic thought. One consequence of this state of affairs may provide the chemist with fruitful material for meditation. Let him contemplate how, recently, the Kobe1 prizes in chemistry hare more and more been assigned to those whose conspicuous service has been the application of chemical principles and methods to other sciences, notably to biological and physio-
Vol. 25, No. 5
logical processes and to industry. The most recent award, to our own Irving Langmuir, is a refreshing and stimulating exception, an award for fundamental chemical development. RELATIOX TO BIOLOGY AKD ~ I E D I C I N E TO the extent that satisfaction can be derived by the chemict from the operations of chemistry as a servant of the other qciences, the present era of development is undoubtedly eminently satisfactory. Perhaps never before have so many striking achievements of applied chemistry been recorded in such brief periods of time. R e need only recall some of the more recent of these. The isolation, purification, identification, and, in some cases, the synthesis of biochemically important materials such as the vitamins and the sterols generally, glandular principles such as thyroxin and cortin, hormones, enzymeq such as urease, trypsin, and pepsin, constituents of the blood, the renewed interest in the structure of chlorophyll and the colored pigments of plant life, are a fern examples in which synthetic organic chemistry is handsomely serring biology and medicine. The biological sciences cannot, however, wait for the still greater perfection of the synthetic chemist’s skill. Therefore, the biologist also utilizes the methods of the physical chemist for a more penetrating study of biochemical and biophysical problems. Reaction kinetics of vital processes are illuminating even where there is darkness as to chemical composition. The effects of radiant energy, quantum processes in photosynthesis, mutations produced by x-rays can be the more readily studied by reason of the contributions of the chemist with simpler molecular systems. The chemistry of colloids with all the newer technic developed to meet its own problems yields to biology (for example, in the work of Svedberg with the supercentrifuge) new data, hitherto inaccessible, as to the size and size diqtribution of important biological units.
RELATIOK TO GEOLOGY The services of analytical chemistry in the field of geology are so obvious as to require nothing more than mention. The era of mineral discovery and classification is now drawing to a close. Physical chemistry, as exemplified in the researches conducted by the Geophysical Laboratory in Washington, indicates a further sphere of usefulness, doubtless to be extended in the future to the study of igneous rocks and ore deposits. Van’t Hoff’s studies of the Stassfurt salt deposits, classical exemplar of such work, is closely paralleled by similar projects in this country. I n the field of economic geology the interrelations with chemistry are a t once intimate and important. The distribution of mineral resources of the world are an international responsibility, a factor of manifest importance in the problem of international friendships and hatreds. The difficulties which arise in world politics from distribution of mineral and, quite generally, natural resources may be intensified because progress in scientific and, most often, chemical achievement may profoundly modify the extent of power accruing from the possession of a raw material. An excellent example of this is to be found in Chile saltpeter. Prior to 1914 this naturally occurring nitrate, required alike for peace-time agriculture and war-time explosive, was almost exrlusively the monopoly of Chile. Today all the great nations of the world are drawing large supplies of fixed nitrogen from the air. Chile is suffering from governmental troubles with increased taxation necessary. The curtailment of her exports is one factor also in the depression suffered by ship-building and ship-operating nations. S o w all monopolies of raw materials may be exposed to similar threats from technical-chemical progress. The efforts of Germany and Great Britain at the present time to derive synthetic oil fuels from coal, to offset the advantages accruing to the United
conies when ehetiiistry is sornetliing far greater than such a collection of empirical facts. We look forward to a inore eornplete mastery of these facts in terins of a more comprehensive tlieoretical treatmelit which underlies them a11. We shall learn to understand with iosiglit and forevision tlie fundairicntal bases upon wliicli rests all our knowledge of CONCLUSION reaetious arid reactioii rates, of steremheniistry and valeiire, , and indced our whole toweriiig I t r r i t ~ s t be eisident Erom what IJRS lieeii mitl that in the Iariiily of the sciences t.liere are niany and varied up~i~irtiiniLies str~icture. To the building of such a struct,iire !re can gladly for tlie exeliange of courtesics. Rut the lifc of ii seiencc wclconie our youtli to furt.lier toil and effort. We should cannot consist. only in semice to iit,lier srieiiws. Were CncmiriLgc them tcr undertake the task with broader lioriaons l 1iterat:ure t,liari we oinselves clremistry faced d l i this fut,iire slime s l i f \vvaukl I~econiethe in ecieuce, iri p!dasophy, r ~ n r in Ciiiderclla o? the sciemw and ret,iim to her baseirrent levels brouglit to our work. We should ask of them, also, liigli in t i l e University of Knowledge. I cannot believe that s u c h rourapc and B patierrce that eventirally will bring its owii is her rlestiriy. Within tile limits of Iicr own family cirde reward since "Knowleclgc accionulateth slowly and not in vain, tliere is still iiiueli room for ilevelopiimrt~ arid extension. with new at,t;rirrment new orders (if lieauty arise." Clieniistry is still largely a descriptive, olisei-vational, and W . ~ I V E ~hlarril '12, IDS:~. ~ ~ e a o r ~ halore ied lite Eenersi riiee~iogol tiie mipirical scieriec. We ranilot be well (:ontent until the time I85tli Meeting ni tltr Amcrirnri Cheniicni Kociely, Washingtun. D. C.,Mardl Statcv Tram l m product,ion of 71 per cent of tlic world's petroleum, is a further illustration of the impact of technical achievement 0x1 the conclusions of ecoiiomic geology. The point need not be further cnipliasized since it helurigs, in part, to tlie t h e m e t h e relation of our science to the state.'
1
nerliy,IND.
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27 I 31. 1933.
Synthesis of Benzaldehyde from Benzene and Carbon Monoxide under Pressure JUDSON $1.H o ~ ~ o wANI) ~ uN O R M A N W. liiias~;,Ihiversity of Illinois, 1 :rbaria, Ill.
The synthesis of benzaldehyde by reaction, os compressed carDon rrmriozicie with Denzerte in lhe presence of aluniinurn chloride is readily accomplislied. Factors influencing the rale of reaction an,d the yield are studied. The process seems to have commercial possibililies.
D
T S in high-pressure technic during the past dcea,dc have made it possible to synthesize from cheaper raw materials many compounds of industrial irnportance previously made from more expensive onrs. In some cases it has becm feasible also tu use more direct synthtitic xnet~hods instead of multistep, complex pr~icedurcs. The synthesis of henzaldehyde from benzene and carlion monuxidc is o? interest, not only liecause both of these adraiitages are obtained, but dso because tho synthesis and rrietliiids developed iue applicable in tlie produt:t,ioii of a large nuinher of other iiidubtrially important arornat.ie aldehydes. deals with a pro of the F r i e d e l and Crafts reaction s n i t ably imidified. The data presented cover only tho use of alumirmni cliloridc as the catalytic agent; exp e r i m e n t s a r e in progress for the iiivcstigation of o t h e r agents active in this type of reaction. The f i r s t record of air a t t e m p t t o synthesize aldehydes directly from hydrocarbons and carbon monoxide ailpeared in 1897, wheii-Gatter-
inann and Koih (6) rep'xted the preparation of p-tolyialdelryde from toluenr: by treating the Iatter with a mixture of gaseous hydrogen elrbride arid carbon monoxide in the presence of aluminum ellloride and r..oprous c.1iloride. Only a trace of aldehyde was fornietl wlien ~lrnninumchloride \\.as used without cuprnus chloride. Kine years later Gattennanri (5) gave a detailed description of various methods of preparing aromatic aldeliydc~. Using the ahove method (8), l i e prepared o-xylylaldehyde, m-xylylaldehyde. nicsitylaldelryde, r,seudoc,iiniylaldeliyde, and diphenylaldeliyde. Ire also sneceeded in preparirig benzaldehyde from henat:ne in a11 snalogotis manner by using a.lunihm hroiriide instead of aluminum chloride. This general nrethod of p r e p a r a t i o n o f a r o m a t i c aldehydes was patented (4). In a patent granted to B oehringer (2) in 1914, an improvement OS the Uatternianii method is described. The s t a t e m e n t is made t h a t good r e s u l t s caii Ire ohtltined in t i m e oases in n4rich t h e Grtttermann pnicess fails to work or gives low yields, if earboii inoiioxide isallowed toact,on the hydrocarborr under pressure in the pres-
