concentrated hydrochloric acid and some resorcin crystalsif a dark red color appears in solution, this is regarded as proof that levulose is present. Glucose should not give this test. By execution of Scliwanoff's reaction we are dealing. with inconvenience that also other sugars give the same test, as, for example, cane: sugar. For this reason to demonstrate the distinction (difference) between the levulose and glucose, we use the reaction, described by me,2 between the sulfur and or-hydroxyketones in the following modification and performance. The small quantities of sugars tested (60-100 mg.) are separately placed in two test-tubes, where the still smaller quantity of sulfur powder (10-15 mg.) is added and in each test-tube 1-2 ~ m of. pure ~ glycerine with one to two drops of lead acetate solution is poured, whereupon both of the test-tubes are simultaneously heated gently over the flame of burner. In a few seconds the liquid in the test-tube which contains levulose, becomes black; meanwhile the liquid in the test-tube with glucose does not ~ h a n g e . ~ The heating must not be of long duration, else the black color appears in the other test-tube with glucose. The black color, which is characteristic for the described reaction, is caused by lead sulfide formed from acetate and hydrogen sulfide; the latter is evolved in the reaction of sulfur with levulose. Inasmuch as,glucose, does not contain the group -CHOH-CO-C, it reacts with the sulfur more slowly and gives the black coloration with delay.
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a ring stand by means of two clamps. An ordinary push button switch (D) was set on the base of the stand to insure that the current would be off when the drier was not in use. The Bakelite around the button was filed down to make contact by foot easier. The students should be supplied with these instructions. (1) Wash the flask well; if necessary use cleaning solution. (2) Rinse twice with tap water. (3) Rinse once with distilled water and allow to drain. (4) Dry the outside thoroughly with a towel. (5) Hold the flask by the neck with the opening downward and heat the body of the flask over a moder-
a ZMACZYNSK~, Corn#. r e d . , 202, 668 (1936); Z. anal. C h m . , 106, 32 (1936).
The same results will he ohtained if for comparison with lewdose instead of glucose cane, milk, and malt sugars are taken.
DRYING APPARATUS FOR FLASKS FLOYD L. ~ A M E S Indiana University Extension, Calumet Eenter, East:Chicago, Indiana
FOR quick drying of flasks and other glassware a current of warm, dry air should be supplied at low pressure. An ord'mary hair drier provides such a current. A reducer and nozzle may be made to introduce the air into the flask. The whole may he mounted vertically on a tall ring stand and fitted with a foot switch. The apparatus in use in this laboratory was constructed fmm a hair drier ( A ) by fitting to the snout a sheet brass reducer ( B ) to which was fastened an eight-inch nozzle (C) of one-half inch copper tubing. The reducer was made and the nozzle attached by silver soldering, since it was found that solder melted a t the operating temperature. The reducer was simply set over t h e snout to simplify dismantling for repair or storage. The drier was mounted vertically a t waist height on
ate flame, freeing all the inner surface from liquid water. (6) Blow out the water vapor with the flask drier. (7) Wipe the condensed water out of the inside of the neck. This inex~ensiveand effective flask drier will be found partiklarly useful in the organic laboratory, where a device of this type is often needed but seldom available. ~
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