VOL. 5, No. 11
AN ELECTFZC STEA~BATE
1447
AN ELECTRIC STEAM-BATH' GnEs B. COOKE,UNIVERSITY OF MARYLAND, COLLEGEPARK,MARYLAND In laboratories not equipped with steam the distillation of volatile, inflammable solvents is very inconvenient and often hazardous. With such a substance as ether, hot water is the only recourse. The hot plate may be used with higher boiling and less inflammable liquids, such as alcohol, but it is far from satisfactory. With such solvents distillation should be accomplished by steam.
D A-Reservoir;
B-Water inlet; C-Capper wire; %Heating E--Outlet for draining flask.
coil;
A steam-bath can easily be constructed for such purposes. An electric current is passed through a coil of resistance wire which has been placed in a three-neck three-liter flask and covered with water. For 110 volts, six feet of wire are used. The wire is coiled by winding it around a pencil or stirring rod. It is convenient to keep the flask from one-half to three1 No originality is claimed for the devising of this steam-bath. It is simply offered by the writer for any value it may have. (Concluded on page 1463)
VOL.5, No. 11
DOCTORATES IN CXEMISTKY C O N P E ~1927-28 D,
1463
(Continued from page 1447)
fourths full of water. The size of the flask and the three necks are merely for convenience. Through each small neck of the flask a copper wire, inside a glass tube, is led to the heating coil. As the coil will have to be renewed (about once or twice a year depending on extent of use) i t is best to solder leads to the ends of the copper wire, and then the coil can be easily connected. By using a two-hole stopper in each small neck, tubes for filling and draining the flask can be provided. A one-hole rubber stopper, through which passes a short piece of glass tubing, is placed in the large neck of the flask. This piece of glass tubing is connected to the bath pan by means of a piece of rubber tubing. It may be necessary to renew the rubber tubing from time to time. This apparatus can be used to generate steam for a steam distillation by disconnecting the rubber tube and connecting the flask directly to the vessel containing the substance to be steam distilled. Below is given a list of material used in constructing the steam-bath. 1 1 1 5 2 1 1 1 1 2 6
Straw ring support (or cork) Three-neck three-liter Pyrex flask Steam-bath pan Ft. glass tubing (Pyrex) 5 mm. outside Ft. glass tubing (Pyrex) 1 cm. outside Two-hole rubber stoppers No. 3 One-hole rubber stopper No. 10 Pinch clamp Small roll tape Short piece rubber tubing Ft. copper wire No. 12 Ft. resistance wires (far 110 volts).
'The resistance wire used is: Chrome1 A, Size 24, 1.53 ohms per ft. Made by Hoskins Mfg. Co., 4445 Lawton Ave.. Detroit, Micb.
