"OPEN-HOUSE" PROGRAMS R. D. BILLINGER Lehigh University, Bethlehem, Pennsylvania
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N INSPECTION of equipment has always been
chemical demonstrations. Some helpful references are considered part of the routine in military and included a t the end of this article. Such remarkable displays as those shown in the Hall naval circles. Dramatic and musical clubs render public performances. Athletic organizations of Science at A Century of Progress ( 1 ) in Chicago and hold their games and pageants. Universities likewise the Franklin Institute in Philadelphia have shown eduare learning the value of public inspections. cators the possibilities of mass education by visual aids. An "Open House" program has been used by many In a very humble spirit the author has endeavored to universities as a means to show some of their facilities relate some of the details of an "Open House" a t Lehigh and the work of their staff and students. University on April 20, 1934. If crowds of 'curious Chemistry lends itself particularly well to demonstra- spectators are any criterion, we think the more than tion. There are many experiments which have become ten thousand visitors who favored us justify a feeling classics to the student of chemistry, hut which are novel of moderate success. to the layman. On the other hand the public has heard Laboratory desks usually offer ample room for disso much of the mystery of science that it is well to show plays and experiments. Some thought must be given some of the simple ways in which chemistry touches to routing people, the use of guides, etc., but these are problems which are quite local. An idea of how our everyday affairs. A successful "Open House" requires much planning, general chemistry lahoratory appeared can be seen in exhortation and training of student demonstrators, Figures 1 and 2. and close cooperation from all concerned. In the A general discussion of the several laboratories, present day when teaching- staffs are apt to be short- with pictures of some of the exhibits, follows. handed, the detail work &ay make serious inroads on EXPERIMENTS I N GENERAL CHEMISTRY time. Both faculty and students often undertake projects which are too ambitious. Many of these experiments can be made quite specThe chief advantages of an "Open House" may be tacular in nature. Among the more successful that summarized as: we have tried are the following: 1. The creation of sympathetic interests of fellow 1. Experiments with Liquid Air (2): Such as freeztownsmen and neighbors. ing mercury, water, vegetables, and eggs. A liquid air 2. Entertainment and education of large numbers of gun can be made from a long glass tuhe. A small visitors. There is a very real opportunity to sow amount of the liquid is poured into the tube and i t is seeds of scientific appreciation which will later bear then stoppered with a cork. By holding the hand around the bottom of the tuhe, the liquid is vaporized fruit. 3. An opportunity to display laboratory facilities and drives out the cork with considerable force. 2. H y d r o g e n : and equipment. 4. ~ x ~ e r i e n ctoe Explosive bubbles (3); balloons to student demonillustrate lightstrators. This ness; diffusion exis perhaps the periments; a n d g r e a t e s t gain. hydrogenation of Practice of this oils. W e a l s o kind develops initiative, and used hydrogen to awakens s t u reduce hot copper dents t o larger oxide, showing the fields and opf o r m a t i o n of portunities. bright metallic copper and water. The JOURNAL All of these exOP CHEMICAL EDUCATION has been periments must a fortunate source be carefully conof ius~irationfor trolled to insure novel ideas in FIGURE 1 against explosions. ~
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3. Carbon Dis p r a y of water oxide: Experifrom a wash botment showing its tle is usually sufficient to start the preparation from marble and HCI action which results in flame and in a Kipp generacopious clouds of tor; a large balance t o demonsmoke (zinc oxide). strate its weight; e f f e c t on lime6. Reactions of water; properties Silver Compounds: of dry ice. I t s Silver m i r r o r s ability to extinwere m a d e b y guish flames can the action of forbe shown b y maldehyde on silpouring C02 from ver nitrate solua large (5-liter) tion. The chembottle over t h e FIGI JRE 2 i s t r y of photogr a p h y was exfamiliar candle staircase. This can be varied by using small gas flames plained. As a stunt, photographic silhouettes were inserted in a trough. A similar experiment was shown in made. This was done by direct action on photographic the Chemistry exhibits of the Hall of Science a t Chicago. paper and a negative silhouette was obtained in a few 4. Atomic Models: Numerous colored atomic mod- minutes. The subject was placed before a white muslin els were constructed by members of the staff and stu- screen, behind which was a battery of six (100-watt) dents. There were also models of molecules of soap, incandescent lamps. The camera was focused on the glycerin, alcohol, sugar, salt, etc. These, being well person, and then a sheet of bromide paper was placed constructed and brightly painted, were curiously in- in the plate holder. - An exposure of 5 seconds was sufficient when a fast grade of paper was used. The print spected if not fully appreciated by visitors. 5. Burning Questions-Pyrotechnics: This table was then developed, fixed, washed, and dried in the had to be carefully watched in order to safeguard stu- regular manner. 7. Experiments with Nitrogen Compounds: Fixation dent demonstrators and their audience. Glass shields between the reaction and the visitors should be used. of nitrogen by the arc process (4) ; preparation of nitric We employed most of the familiar experiments on acid by distillation from sodium nitrate and sulfuric combustion. Fires were ignited with water and sodium acid; an ammonia fountain; exhibits of important inperoxide; phosphine was prepared and the rings of dustrial products containing nitrogen. 8. Carbon: Absorptive properties of carbon; dephosphorous pentoxide formed; solid alcohol was colorizing brown suzar and pink soda water; uses in gas masks; displays of allo&opic forms of carbon and glass reproductions of famous diamonds. 9. Light: The chemistry of illumination in all ages can be shown by a display of old oil burners,
made from ethyl alcohol and calcium acetate, then ignited by placing it on crystals of GO3; the action of sodium on water was shown; spontaneous combustion was produced by the action of solid potassium permanganate and glycerin. Another reaction of interest was that of water on powdered zinc and ammonium nitrate. The finely mound nitrate is suread on filter paper, and over it-aihin layer of zinc &st. A small
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lamps, candles, gas mantles, and incandescent bulbs. Our museum contains many valuable antiques which are adaptable to such a display. Charts explaining details of illumination were prepared. PHYSICAL CHEMISTRY
In physical chemistry there were several features whicb seemed of especial interest; among others a mercury exhibit which showed the purification and uses of this element. Mercury was distilled as shown in
FIGURE 5
Figure 3, by heating in a distillation flask over an electric coil. The vapor was cooled in an air condenser and purified liquid w a s c o l l e c t e d . Another means of purification, namely by dropping a thin stream of liquid mercury through a tall cylinder of dilute nitric acid, was shown. Thermometers, barometers, and a mercury vacuum pump were exhibited to show uses of mercury. Applications of photo-electric cells to chemical measurements were demonstrated (Figure 4). A potassium perrnanganate-oxalic acid titration was conducted in a beaker. A beam of light was passed through the beaker to a box containing a photoelectric cell connected to an electric buzzer. When an excess of permanganate solution was added the interrupted beam of light was detected by the "electric eye," whicb in turn caused the buzzer to sound. A similar arrangement was used to signal a sound when a battery jar was filled with fumes of ammonium chloride. Descriptions of uses of photo-electric cells are current in the literature (5, 6). Brownian motion was demonstrated by observing a gold colloid in the ultramicroscope. A number of the more spectacular colloidal experiments were grouped in a special research laboratory. Among these were all types of emulsions, gels, foams, Liesegang rings, and the
always popular silicate garden. The latter grows quickly when small crystals of metal salts are sprinkled into a jar of dilute sodium silicate. It can be effectively displayed by indirect illumination either from below or from the side. To simulate the kinetic theory of gases (7) a pith ball bombardment tube was constructed. In a strong glass tube approximately 50 cm. long and 2.5 cm. in diameter were placed 10 cc. of mercury and a dozen or more small pieces of cork. The tube was then sealed and clamped upright. By gently heating a t the bottom the bits of cork soon danced and bombarded each other in the tube. In the field of electrochemistry the electrolysis of water was shown. From a slightly acidulated water solution the hydrogen and oxygen were collected, reunited, and exploded. This was done periodically by an automatic circuit breaker. No chemistry "Open House" would be complete without a glass-blowing exhibit. Many laymen have never seen the simplest glass-working demonstrations and an interested group of spectators will always be
found around a bench where an adept student is performing ordinary operations on glass vessels. In addition we also exhibited several tables of interesting chemical glassware. Figure 5 shows a few of the specimens which any laboratory can display. QUANTITATIVE ANALYSIS
Our quantitative analytical laboratory showed how the analyses of iron and copper ores and steel products are conducted. A combustion train for the analysis of carbon in a steel sample is shown in Figure 6. Visitors were also shown how a chemist tests such everyday materials as milk, ice cream, water, baking powder, and urine.
T h e assay laboratory, which is a branch of our analytical department, showed how gold and silver ores are analyzed by fire methods. There is always interest in the extraction of precious metals, and this proved to be a most popular exhibit. In another section of the building our chemical engineering department demonstrated gas analysis with a Burrell outfit. This was part of a larger gas absorption tower system (Figure 7). There were also tests on coal, oils, and gases. An exhibit of balances and scales should interest most visitors; particularly if a variety of different types is available. We were fortunate in borrowing an old brass scale which was used in the first drug store in the United States, the site of the present Rau Pharmacy a t 420 Main Street, Bethlehem, Pennsylvania. There was also displayed a balance used by Professor C. M. Wetherill (8) during the Civil War. Contrasted with these were the modern balances of the chainomatic type. As a popular stunt we weighed names of visitors. Names were written with a wax pencil on small slips of paper, and these were readily weighed on a torsion balance (9). One bench of balances displayediis shown in Figure 8. Naturally equipment of this kind must be
carefully attended to prevent the over-curious from damaging expensive instruments. ORGANIC EXHIBITS
Organic chemistry is so varied that here there are countless opportunities to demonstrate the contributions of chemistry. to daily life. In our exhibits students were preparing such well-known compounds as aspirin, mercurochrome, cincophen, and atophan. In the field of dyes, indanthrene was made by the fusion
biological stains, medicines; pigments, lacquers, a n d compounds used in chemical warfare. Borrowing a page from the Fourteenth Annual Exposition of Chemical Industries (lo),we had a display of "Children of the Depression2'-products made during the last four years. Many of these were contributed or loaned to us by chemical industries. The ready response which we received from almost all the companies approached was most helpful. There were new anesthetics, solvents, vitamin extracts, plastics, etc. CHEMICAL PRODUCTS MAP
A project which requires considerable advance work is the construction of a chemical products map. This might well be undertaken by an entire section of students in general chemistry. The map shown in Figure 9 measures eight feet square in the original. It was patterned after a map printed for the National Wholesale Druggists' Association, edited by Dr. H. V. Amy, College of Pharmacy, Columbia University. Our map was painted on white, filled muslin, of the type used for window blind material. It was supported by a frame of beaver board. Samples of products were glued to the map with Ambroid cement, to insure tenacity. Each product was identified by its name beneath it. To save labor in hand printing, these names were cut from chemical label books which are published by most chemical supply companies. The labels are gummed and can be quickly attached.
chemistry was created by showing pictures of famous chemists and classical books of various periods. Books must be shown under glass cover to prevent damage by handling. An interesting series of pictures of famous American chemists is that published by D. H. Killeffer, formerly associate editor of Industrial and Engineering Chemistry. Each portrait is accompanied by a short sketch of the subject's achievements. We have also a t various times equipped a room as an alchemist's shop and performed various chemical tricks under the guise of alchemy (12). Black magic always has an attraction for the uninitiated. A possible set-up for such a program is shown in Figure 11.
We also used this map to show where Lehigh chemists are employed. With large numbers in certain areas it is simpler to stamp the number for each State on a small disc and attach this by means of a colored map pin. The map was placed in a prominent location, and attracted much attention. Inquiries and comments on it by high-school teachers have led me to enlarge upon the details. HISTORY OF CHEMISTRY
The preparation of small-scale laboratories or dioramas can be utilized to develop a certain interest in history of chemistry. In the Hall of Science at A Century of Progress Exposition, there were excellent models of an alchemical laboratory and of Lavoisier's laboratory. We undertook to copy the latter and also to reproduce a model of the famous painting of Davy washing dishes in Faraday's Laboratory. We were aware that there is no historical basis for the DavyFaraday tradition (11), but i t makes a good subject, typical of the early nineteenth century. A picture of our Davy-Faraday laboratory is shown in Figure 10. The front of the model measures 28 by 45 inches, and the depth is 25 inches. Indirect lighting was obtained by placing electric bulbs behind ground-glass windows. The figures were carved from soap and then painted. Once started the project was watched and aided by many of the students and staff. Some blew glassware, others constructed and painted benches, shelves, and laboratory equipment. Some artistic direction is necessary, but almost a n y volunteer workk can assist somewhere. F u r t h e r interest in historical
LECTURES, MOVIES, AND CHARTS While most of the visitors to an "Open House" come to see and not to listen, there are a surprising number of the more serious-minded who will sit through a short lecture or series of demonstrations. In our main auditorium we conducted a continuous series of talks by staff members and student demonstrators on vacuumtube phenomena, electrons, chemical activity, and flame speeds. These were accompanied by experiments. In another lecture room there were moving pictures showing the chemistry of sulfur, glass, and alcohol. A chart display of chemical quackery in one of the smaller rooms was eagerly inspected. Here were told interesting truths about some popular products, as disclosed by medical and research bureaus. We employed numerous charts, pictures, and flow sheets of chemical processes to supplement our displays of chemical products. These were arranged in halls connecting the various classrooms and laboratories. SPECIAL FEATURES
Each institution has certain specialties which can be featured. We tried to popularize some of our researches in chemical engineering; investigations of oils, paints, patent leather; textile studies of wool and silk; X-ray researches on arrangements of atoms and molecules;
vapor pressure and calorimetric studies. Enumeration of details would become tedious and there is no attempt being made to mention everything shown. Suffice it to say that almost any research can be shown to advantage providing that proper captions and signs be used. A well-informed student demonstrator will certainly interest some of the visitors in his
work and the boy himself will be gaining valuable experience. Our experience with "Open House" programs has been interesting and also a t times rather trying. Some advantages have been related. Certainly an occasional "Open House" will stimulate everyone to new ideas, and a t this writing the idea seems to be popular.
REFERENCES
MUSKAT,InvrnG E., "Chemical exhibits a t A Century of . (July, 1933). Progress," J. CHEM.E ~ u c .10,387 CADY,H. P., "Liquid air," ihid., 8, 1027 (June. 1931). ULLMANN, H. M.AND HAZE-ST. T. H., "An oxy-hydrogen soap-bubble pipe," ibid., 11, 113 (Feb., 1934). RILEY,H. M., "Demonstration of nitrogen fixation.'' ibid., 7, 2167 (Sept., 1930). MCMASTER, A. J., "Photoelectric cells in chemical technology," Ind. Eng. Chem., 22, 1070 (Oct., 1930). PARTRIDGE, H. M., "Applications of the photoelectric cell to chemical analysis and control." Ind. Eng. Chem., Anal. Ed., 2,207 (July, 1930).
HOLMES,H. N.. "General chemistry," The Macmillan Co., New York City, 1930, p. 56. SMITE, E. F.,"Charles Mayer Wetherill," J. CXEX.Eouc., 6, 1076 (June, 1929). DEGRAY.R. J., "A new surface tension balance," Ind. Eng. Chem., Anal. Ed., 5,70 (Jan., 1933). "Children of depression." Ind. Eng. Chem., 26, 3 (Jan., I,A"-A,. iCllA~ Note, J. CEEM.EDUC.,8, 859 (Apr., 1930). BILLINGER, R. D., "A night in alchemy," ibid., 5,715 (June, 1928).
