DISPLAYING CHEMICAL EXHIBITS* EGBERT K. BACON Union College, Schenectadr, New
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HE display cases for chemical exhibits that are illustrated and described here are in use in the chemical laboratory of Union College. The cases, which were all designed and constructed in the chemical laboratory, afford an effective and inexpensive means of placing on permanent display typical exhibits of materials that are associated with the most important chemical industries. The educational value of chemical exhibits may be lost easily through improper display. I t is frequently customary to place exhibits in large wall cases, which are usually located in a room designated as a chemical museum. Another common plan is not to place exhibits on permanent display, but to store them in boxes or cupboards. The disadvantage of the first method of handling exhibits is that they may be seen only by a special visit with, perhaps, the dead impressions of museum curios. Furthermore, large masses of material grouped together have a bewildering effect on the observer, with resulting disinterest. Storage of exhibits may keep them clean and intact, but does not permit prolonged display, as their use may be confined to a single hour's exhibit on the lecture table. One solution to this problem of display is by use of small glassed-in wall cases. These cases have been standardized to overall dimensions of 20'' X 301/%''and about three inches in depth. The sides of the cases are constructed of half-inch cheap lumber, fitted and held together by 2" X 3'/4" angle irons. The backs are constructed of composition board, and angle irons, fitted a t each back corner, give the frame rigidity. The * Presented before the Division of Chemical Education at the ninety-third meeting of the A . C. S., Chapel Hill, North Carolina. April 13. 1937.
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boards of which the sides are constructed are rabbeted both front and rear to admit ordinary standard 2g3/4" X 30" window glass in front and the composition back in the rear. Wooden strips 3/4" X '/pl', which are screwed into the frame, hold the glass in place. As many
shelves as may be desired are fitted into the frames and held by nails through the sides. The nail holes are countersunk, filled with putty, and the entire case painted a flat white or cream color to harmonize with the walls on which they are hung. Figure 1 shows three of these cases mounted on the wall of the Chemical Laboratory. Each case is devoted to a single exhibit or, a t the most, to not more than three exhibits. These need not
be related in any way, but are selected to give balance and color to the entire case. For example, the almost too colorful nature of a case devoted entirely to synthetic plastics and the too colorless nature of an exhibit of rubber or neoprene may be off-set by a combination of the two. .- We have thought it best to let each exhibit speak for &self, although a neatly lettered sign for each gives the nature of the exhibit and credit to the manufacturer
is that material cannot be easily removed when once arranged. This could be overcome by construction of a hinged glass door that may be locked instead of the glass held in by screws. However, this adds both expense and some extra labor to the construction. On the other hand, this condition may be really an advantage as material cannot be disarranged, broken, or lost in the process of repeated removal. If there is not enough wall space to display all the exhibit material on hand, there may be a planned rotation or change of cases, or the material in them. Another use to which these cases may be put is to the display of certain laboratory preparations such as crystals, colloidal systems including sols, liesegang rings and other gel reactions, inorganic and organic preparations, etc. The advantage of displaying exhibits in the manner described here may be summarized as follows: First, the displays are all single units or several smaller units, which may be arranged in a colorful and
FIGURE 2.-ILLUMINATED SHOWCASE FOR EXHIBIT OF
BULKYMATERIALS
furnishing it. In some instances, where further information seems necessary, small typed cards give the required description. K.Where the manufacturer has supplied a mounted display, we have built the case around the display board, following the procedure as described for the standardized wall cases. Where the bulkiness of the material to be displayed does not permit inclusion in one of these cases, we have placed it in an ordinary showcase equipped with showcase lights. This, however, has the objection, as previously mentioned, of massing together too much unrelated material. Figure 2 shows the effect of the lighted showcase. For the most part, we have placed the exhibits on the walls flanking the lower corridor of the chemical laboratory through which everyone must pass to gain access to the various offices and laboratories. Here they do the maximum of service. Some cases have also been placed on the other floors of the building where wall space is available and where the exhibit will show off to advantage. Figure 3 shows the general effect obtained as one enters the lower corridor of the Chemical Laboratorv. One objection to the type of wall case described here
attractive manner. They do create and hold interest. Second, they are constantly on view to students passing to and from classes. Visitors find them a continual source of interest. Third, the displays remain intact and free from dust and other contamination. Fourth, they permit the bare walls of a chemical laboratory to contribute to the cause of visual education. These displays would not be possible without the generous cooperation of numerous manufacturers of chemicals and chemical products. While the sources and types of material have been far from exhausted, we have a t present sixty-eight different displays that have been contributed by sixty-two different manufacturers. Our requests for material have been modest, and rarely have we found a manufacturer unwilling to coiberate. The displays may be classified under the foilbwing
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groups: Chemicals, organic and inorganic; Cellulose ments, and Varnish; Petroleum Products; Silicates and and Cellulose Products; Electrical Supplies; Food Glass; Synthetic Plastics and Resins, and MiscelProducts; Metals and Metal Products; Paints, Pig- laneous.
