The new chemical section in the Deutsches Museum at Munich

Describes the new chemical section in the Deutsches Museum in Munich, including exhibits on modern and applied chemistry...
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THE NEW CHEMICAL SECTION I N THE DEUTSCHES MUSEUM AT MUNICH' RUDOLF SACHTLEBEN Deutsches Museum, Munich, Germany ( T r a n s l a t e d by R a l p h E. Oesper)

Tm Deutsches Museum is one of the main attrartions of the city of Munich. Sinre its opening (1925) about 16 million visitors from all rorners of the world have viewed it,s collections. They have been entertained and instructed by its exhibits in the fields of science aod t,echnology. Many young visitors have beer1 influenred greatly in their rhoire of a life-work by what they saxv and heard there. The founder of this great educational institution rvas Oskar von Miller, a Munich construction engineer. His enthusiasm prompted voluntary vontrihutions of lahor and planning, gifts of apparatus, machinery, building material, and money. The Deutsches Museum is made up of a great romplex of buildings on an island in the Isar, whirh flows through Munich. T o make the sciences and technology popular, von Miller employed three methods: lert,ures, technical literature, and exhibits. Arcordingly, on the "Museums-insel" there are now lecture halls, for experiments and projections of all kinds, a large library buildiug which houses terhniral aud srient,ific literature from the entire world, and a third building which contaius the museum itself. T o see all of the latter means a journey of approximately eight miles through rorridors and aisles. This distance is now shorter hrrausc of the damage in." flirted by the bomhs of World War 11. Fortunately, t,he valuable historiral objects were placed in safety. The reroustruction of the building '.. and exhibits is now in full prog,,. ress. "Every ratast,rophe yields an opportunity." The demolition and damage provided an opportunity to erect a modern museum structure i n place of the outdated

building and to remodel the crowded exhibits. CHEMICAL SECTION REBUILT

A descript,iou of the former rhemiral sertion was 7, 702 (ll):30), hy Wilhelm given in THIS JOURN-4~, l'randtl, who died late in 1956. The former arrangement mas that of a textbook, Like many texthooks, it had the characteristic of heing romplete hut also was not equally attractive in all of its parts. Moreover, it had become outmoded in its 25 years of use herausr rhemistry is a living and progressing srienre. The present authorit,ies have tried to select a romparatively few rhemical facts and t o present these as attrartively as possible. In the planning, an idea put forth by Justus von Liebig was the guide, namely: "The history of a science is a p a g e in the history of thr human mind." Thisroorept was readily applied in rearranging the museum. I.'our historiral laboratories were set up. They demonstrate the development and problems of the alchemical, Middle Ages, Lavoisier, and Liehig periods. Each was faithfully erected in it,s proprr style in a room mhirh pirtures its rontemporary architcrtural and rultural relatio~lships. Arrordingly, the visitor passes through the epochs of the Gothir, the




I E D I ~ R 'NOTE: s The sreompnnying article appear8 at the 1.0quest of readers who rocall with pleasurc thp enrichment afforded their European travels by having marl Dr. Oesper's papws oi' the


Ilr. Ssehtlehen and his staff rordi:~ll,vinvitesllrendersof~~~s JOURZAI. who may be visitors in Munich t,o enjoy II husmxn's halidsy in t h ~ 1)cutsches Museum.

VOLUME 34, NO. 6. JUNE, 1957

The "Lauoirier" Laboratory

Family Tree of Coal Tar P ~ o d u c t s

I h n r h Itevolutiol~,the Ilomalltir, and the present. .\I1 of the rooms are furnished with original apparatus or aut,hentir reprodurtions. 1"undamental discoveries of thc various periods have heeu st,ressed as milcstolles in chemical understanding. In the alchemy of the Middlc Ages, the chemical world pirture mas spirit,ual, and the "scient,ist," was a pious man, as were t,he master huilders of thc Gothir rathcdrals. Hc sought the relation between t,he microrosm (earth and man) and the macrocosm (heaven and God). Whereas the scholars of antiquity left "the pigment grinding and salve cooking" t,o the lomly slaves and handnorkers, alchemical experimentation began in the medicval laboratories of the Occident. I t arose out of the urge for moral and material clarificat,ion. This impulse later degenerated into illusory and decept,ive goldmaking. On the ot,her hand, these efforts led to the great. inveillion of the art of distillation. Tools, which previously had been used only by artisans, hecame scieutific aids. Paracelsus (1493-1541), the great natural philosopher and physirian, taught the prcparation of medicir~alsfrom healing herbs and minerals and thus founded the art of the pharmacist. Gold, ruh.v glass, Enropean porcelain, and other chemical products were discovered empirically. The mineral arids were prepared evellin considerable quantities in the so-called "Lazy IIemy." During the French Revolution, the "Goddess of Reason" ascended the throne of scicnre. Lavoisier founded a materialistic chemistry, which experimentally decomposcd the natural materials and studied thek individual constituents. The first special laboratory techniques mcrc developed, such as means of analyzing the diamond and the air, and procedures for synthesizing water and saltpeter. A chemistry of gases mas rreated, mhich, harking hack t o the earlier macrocosmos roncept, mas ralled "pneumatic" chemistry (pneuma = soul or breath). T h r experimental mat~ipulationof the

gases led to the erection of the osygeg.ent,heory. Ry purely mat,erial rousiderationr;, it hrought respiration and rombustion into an i~ltelligihlc relationship. Elertririty and the vacuum becamc tools of the rhcmists; analytical halances, the harometer, thrrmometer, and microsropr hecame indispensahlc in thc laboratory. The third room is the Liehip laboratory: an cxact replica of the famous tearhing laboratory iir Giessen. He markedly enrirhed rhemiral lahoratory technique, for instance, through his apparatus for the ultimate analysis of organic compounds, slid by his popularization of the condenser I\-hich has heen (incorrectly) given his name. He e1111.idated the chemical conncctions betneen the animal kinadoms h~ and veeetablc .. -. introduring t,he aquarium into a biological equilibrium. It became kno~r-nin Germany as the "Jiehig world i n glass." A "trec" shows Liebig as the progenitor of a family of scient,ists fro111 which have now issued 34 Sohel laureates. This noble rompany includes thr Americans: T. W. Richards (1914), the master determiner of atomic wights; Iving Langmuir (19:?2), aut,horit,y on surfare rhemistry; the hiochemist Fritz A. Lipmann (3 953); and Glenn T. Scahorg (1 951, the discoverer of the trans-uranium element,^.

MODERN CHEMISTRY EXHIBITS I t has heen the intent t o reveal t h r mode of thought and the research methods of the modern chemist. In these exhihits there has heen no effort to show everything, hut rather some important facts are emphasized and brought toget,her. Modcnl chemistry deals ~ i t h elements and compounds; so characteristic examples of earh have heen selected for exhibition. I t has heen a chararteristic feature of the Deutwhes Museum that the visitor wvould have ample opportunity to push buttolls and set models into motion. I n the rebuilding of the chemical sectioi~an effort n-as made t o extend this tradition to chemical proccsses. For example, it is now possible hy pushing a hut,ton t o hring together any two desired liq~iids. After the reaction h e t ~ ~ e ethem n has heen completed, the reaction vessel is emptied, rleaused, and returned to its original plare by means of an invisible controlling mechanism. The visitor mag, for instance, see the detect,ion of t,races of iron(I1I) hy the color reaction with thiocyanate. Or a carbohydrate (sugar solut,ion) is s h o m to yield rarbon when treated with conrentrated sulfuric acid. Chemiluminescenr~ is demonstrated mith luminol and hydrogen peroxide. The visitor can detect elements hy flame reactions and also by spectroscopic and radioactive methods. Radioartirity is shown in considerable detail by n~eansof a JOURNAL OF CHEMICAL EDUCATION

Vilson cloud chamher, a Geiger counter, and hy autoradiographs. The periodic system of the elements is shown in t,he form of a large spiral, beginning with hydrogen and closing with mendelevium. A11 of the long-lived elements are represented hy act,ual samples, and the history of their discovery is out,lined. The entranre to the c $ n h room i-i flanked hy a Ilonigschmid apparatus for the determinat,ion of the atomic weight of radium, and by t,he original apparatus with which Otto Hahn rhen~il:ally discovered the fission of uranium and thus iliitiated t,he era of at,omic energy. Original samples of the earliest enriched uraniun-lead introdure the concept of isotopes. A comparison of the vapor pressure of normal and heavy w a t ~ is r also demonstrated. Sinre t,he former atom models, oonstrurted from ping pang halls and mire rings, no longer conform to the present state of atom research, new repre~ent~ations were sought. Giinther Scheihe, professor of physical chemistry a t the Technical University of Munich, developed nex n ~ o d e l s . ~These show the inner strveture of the atoms, arrording to the present conreptions of \rave mechanics, as colored luminous clouds. Such models were constructed for t,he elements of t,he first tn-o periods. Other models show the hydrogen atom in various excited states, and in the molecular form. Fluorescent synthet,ic materials, phosphorescent paink, and dark ray emitt,ers were used in t,hese ronstructions. The visitor, hy pressing a hutton, call see the arrangen ~ e n tof the at,oms in rlystals. This is made possible by a nevly ronstrurt,ed Laue apparatus with a novel Siemens X-ray atttlrhment. A single crystal of aluminnm is used; it is rotated int,o different positions hy t,he 7-idor during the irradiation. Simple experiments demonstrating the formation and art,ion of ions and illustrating the stoichiometric laws can he performed. Clystal models of diamond, aluminum, sodium rhloride, and urotropine are shown; the dimensions sword with the measxrements of the respective J,wr diagrams. APPLIED CHEMISTRY EXHIBITS

large hall is devoted to applied chemistry. Many products used in dai1.v life have been the fnlit,s of t,his I~mnrhof our science. Organic synt,hesis had its hirt,h ill the laboratory preparat,ion of urea. One of the treasures of the oollert,ion is a small sample of the material prepared hy Wohler himself in 1928 and autographed by him.3 From Wohler's disrovery grew the farto~y-scaleproduction of indigo and the Reppe chemi ~ t These ~ . ~marvels of modern chemical technology are reprcscnted on five columns. -4 great family tree of coal tar produrts shows t,he chemical relationships and 'strps in the synt,hesis of 40 organic products. F,xplanat,ory placards, san~plesfor testing the odor, and

VOLUME 34, NO. 6. JUNE, 1957

A u t o m a t i c Appnrstu. for Releesing Elerneniary Carbon from sugar

colored lights make it casicr for the visitor to wrderstand ~ v h a tis hefore him. Of sperial interest to our present riviliaation are the macromolecular products from t,he retort, and autoclaw: t,he "tailor-made" synthetirs and chemical fibers. These new materials are shown hy an extensive exhihit, in whose assembly the advice of Dr. I