AL EDITION
160
Vol. 1, K O . 3
tions of the signal shaft may take place. This means that a sample may be compressed for 1 second and its recovery observed after one or any whole number of seconds. The gage, 9, is of a special design. Its stem, as well as other parts, is hollow. It has only a small hair-spring to take up lost motion. This makes for extreme lightness and a small load upon the sample. The dial of this gage is graduated to 0.001 inch; the extreme travel of the stem is 0.5 inch. To lift gage extension rod, 4, off the sample, the eccentric wheel, 28, bearing against a lifting rod, 29, is provided. To control the temperature of the sample, 19, the upper and lower plunger, 20, 21, are surrounded by an oven, 23, equipped with thermometer, 24, and thermostat, 25. The samples are inserted and removed through a small door. Illumination within the furnace is provided for by a small lamp, 26, above the small door, 27, and attached to the large door. Only stocks that do not recover completely in 1 second may be studied with this instrument.
A Modified Pauly Receiver' J. B. Brown DEPARTMENT OF PHYSIOLOGICAL CHEMISTRY, OHIO STATEUNIVERSITY, OHIO COLUMBUS,
modified Pauly receiver for use in fractional vacuum A distillation is shown in the accompanying photograph. The receiver is constructed from a standard 250-cc. Pyrex
Figure 3-Front
View of Automatic Plastometer
By prolonged depression of the levers, 16 and 17, any number of revolutions may be allowed-that is, any number of the to-and-fro motions of the toggle, any number of compressions, and any number of light signals may take place. By momentary depression of the yoke-sleeve lever, 16, and prolonged depression of the clutch-sleeve lever, 17, only one motion of the toggle is allowed, but any number of revolu-
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suction flask. In the base of the flask are blown six depressions about 20 mm. in diameter. To each of these is s e a l e d a piece of 12-mm. Pyrex glass tubing with 2mm. walls. Each of these legs is 120 mm. long and slopes outward on a line parallel to the side walls of the flask. This arrangement makes possible the use of a 500-cc. receiving flask on each leg. The adapter is made from ordinary glass, the lower end being a t least 8 mm. outside diameter, in order to cut down bubble formation and spattering into more than one depression a t the bottom of the Aask. A similar receiver w i t h eight legs may be made from a 500-cc. Pyrex suction flask. The receiver w o r k s m u c h more successfully in the laboratory than any Pauly receiver that the writer has been able to obtain on the market. The glass blowing on the apparatus illustrated was done by R. B. Leonard, of the Department of Chemistry. 1 Received
Figure 4-Top
View of Automatic Plastometer
April 6, 1929.
Dutch Scientist Aids in Defining Atomic Spectra-The Bureau of Standards, with the assistance of T. I,. de Bruin, of the University of Amsterdam, who has completed his work in the Department of Commerce, has established a record in scientific research by defining and explaining no less than six different spectra in a period of ten months. These include the halogenschlorine, bromine, and iodine-the heavy rare gases-krypton and xenon, and the more familiar but deadly metal, arsenic.
