'(5) TREADWELL, F. P. AND W. T . HALL, "Analytical chemistry," John Wiley and Sons, Inc., New York City, 1932, Vol. 11,
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(6) WELLS,H. L., I.Am. Chem. Soc., 42, 411 (1920).
A DEVICE FOR DRYING LABORATORY GLASSWARE A. L. DUCOURNAU Louisiana State Normal College, Natchitocher, Louisiana
In the laboratory it is often necessary to dry con. denser tubing and other glassware in a limited amounl of time. Too often supposedly pure chemical com-
(7) WILLARD, H. H.
AND N . H. F-AN, "Elementary quantitative analysis," D. Van Nostrand Co., Inc., New York City. 1933, p. 35.
coil can be made by filling the pipe with sand and then winding i t around the six-inch cylinder. A six-inch pipe or post would serve the purpose. A perfect coil can thus be made. The coil is connected to the source of air, while a globe valve is used to regulate the flow of air. The coil is placed over a source of heat, so that it can be well heated. The air becomes heated as i t passes through the coil, and as it comes out of the coil it is blown into the glassware. This set-up has given service in our department for several years.
REDUCTOR TUBES OF RUGGED DESIGN HAROLD G. CASSIDY Yale University, New Haven, Connecticut
Many reductor tubes as sold have a very wide opening a t the top, something like a magnified thistle-tube. While this large opening facilitates pouring into the tube and is convenient for holding a quantity of liquid, yet the tube of this design has two severe disadvantages: it is far too easily broken, and it presents a very large surface for evaporation. We have found it convenient to make reductors of a design such as that shown in the figure. They arerugged and will hold about the same amount of liquid as the wide-topped variety. When they are not in use a one-hole rubber stopper is put in the top opening. This prevents too rapid evaporation of the dilutesulfuric acid used to keep the reductor moist. We make these reductor tubes from 18mm. I.D. Pyrex tubing and seal a stopcock to the lower end. A rubber tube and pinchclamp could be used instead of the stopcock.
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pounds contain moisture on final distillation, simply because a small fdm of moisture was present on the glassware. A very efficientand convenient device for drying glassware was constructed out of the most inexpensive material that could be purchased for such a purpose. If the laboratory is equipped with compressed air this device works excellently. If compressed air is not available a foot bellows can be used as the source of air. The dryer (see figure) consists of a ten-foot piece of onequarter-inch iron pipe made into a six-inch coil. This
