A Portable Steam Baih St,eam bat,hs have t,raditianallv found meat use in oreanic chemistrv labs where flammable solvents oreclude used a portable steam hath This bath is constructed utilizing a 5-in. copper water hath (similar to Arthur H. Thomas #9864) and an inexpensive immersion heater (200 W; obtainable from most hardware and vrtriety stores for 59-79 cents). The outer ring of the water bath is notched so that the immersion heater fits snugly into the bath. Tho hath is then filled with water, the rings put in place, and the heater plugged in. In thc ease of the 5-in. baths i t takes approximately 5 min. to reach the boiling point. Initislly it was feared that the water hath would boil to dryness in 8. short period of timo and burn out the immersion heater. T o solve this problem a second notch was cut in tho outer ring and a bent 8-mm glass tube was inserted into it, extonding downward into the bottom of the bath and providing a n entrance port for a dow stream of water. A piece of rubber tubing was then attached to the exit m r t of the bath to take care of the overflow. With this adaptation, the water level in the bath remains constant. Althodgh the incorporation of a constant water level was initially conceived as a safety feature it also provided for more flexibility since the water temperature of the bath can be varied from room temperature to boiling by adjusting tho flow of water. Without the constant water How it was found that (with all but the center ring in place) the bath could be kept plugged in and used for periods up to about a n hour with no difficulties. No problems have been encountered with the rlwtt.il.t~Iviwuils supplying I11c laboratory when as many as 35 of these portable steam baths are operating a t the samc time.
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236
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Journal of Chemical Education
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