LABORATORY for GENERAL CHEMISTRY N. BEVERLEY TUCKER Virginia Military Institute, Lexington. Virginia
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NEW laboratory for general chemistry, recently completed a t The Virginia Military Institute, embodies several features which have proved their worth in actual experience. Since the whole of the equipment was built by local workmen a t comparatively small cost, a brief description of the outlay may be interesting. The laboratory with connecting offices for the instructors is housed in the top floor of a building recently completed, adjacent to the chemistry building and connected to it through an enclosed corridor bridging a space of some 25 feet. The laboratory proper is a room 86 by 40 feet, lighted on three sides by large casement windows, and having a nearly vertical skylight running almost the length of the room. Ventilation of the room itself is provided for by two Univent radiators a t opposite comers. In addition to the windows the whole skylight may be opened in good weather. The room is completely fireproof, with white painted brick walls and concrete floor. The desks were designed to provide locker space for four individual sets of apparatus under each working space, to accommodate four different sections on successive days. Each cupboard has a built-in drawer, such that one catch serves to lock both drawer and locker, thus making for economy in construction and use as well as neatness of appearance. Tops are of alberene stone, purchased in rectangular sections and sawed to shape. These desks are in three benches of eight units each (unit is 5 feet 6 inches in length) and three of four units each, providing working space for seventy-two men. Each desk is provided with water and gas lines, the latter being run as a continuous pipe through the reagent-shelf supports. Instead of individual sinks, a lead-lined trough was built running the length of each section and sloping to one end. At proper intervals an offsetin the trough furnishes a sink beside each work space, and all drain into a large sink with a 2l/%-inch drain a t one end of the section. The elimination of many hidden drains makes for simplicity of plumbing, but more important, minimizes clogged drains, which are encountered all too frequently. The one pipe to the sewer is easily accessible for repairs. Ventilation and the elimination of vapors is provided
for through the medium of flumes along the top of each section, three sides being of California redwood heavily coated inside and out with alphatum and "Troplite," the bottom consisting of a wedge-shaped metal strip extending as an apron 8 inches out over the desks (see drawing). At the vertex the metal is pierced with from six to ten 1/4-inch holes (depending on the distance from the center) to admit gases to the flues. Each section of this trough is connected through a sheet-metal flue which is exhausted by a 3-foot,. Buffalo-type C-L fan driven by a 750 R.P.M. 1 H.P. motor. This arrangement has proved very satisfactory for the elimination of the greater part of the fumes created by the students a t each unit. For example, phosphorus can be burned in an evaporating dish held several inches below the metal apron with almost complete removal of the phosphoric oxide fumes. This arrangement works much more satisfactorily than most of the downdraft desk hoods usually provided for, and is superior to most overhead hood arrangements in that it is neat and compact and decreases visibility and light very slightly. The top of the flume serves as a shelf for bottles, and takes up very little more space than the conventional type of reagent shelf.
