IMPROI'ED
E X T R A C T I O X APPARATUS.
123
At every instant, by this arrangement, a minute fresh portion of salt is introduced into the flame with the result of making a perfectly uniform light, which can be used for hours without any perceptible variation. T h e inechanisni of the apparatus is so simple that no further descriptioti is necessary. T h e polariscope should be so directed toward the flame as to bring into the field of vision its niost luniinous part. T h e platinuiii wheels are adjustable and should be so arranged as to produce between them an unbroken yellow flame. T h e wheels are eight cm. in diameter and driven a t a rate to make o;ie revolution in six to ten minutes. [ C O N T K I R V T I O N S FKOM THE C € I E M I C . l L 1,AROKATORY OF AGRICUI,TLJRF;. No. 5 . 1
c.s. DEPARTMENT
II'lPROVED EXTRACTION APPARATUS. BY H. W . U'ILEY. K e c r i v d blny 26. 189j
T
HE apparatus for the extraction of substances soluble in
ether, alcohol, etc., described in the j o u r n a l of Analyticul and Apfllied Chemistry for February, 1893, pp. 65, et sep., can be more conveniently operated when constructed in the manner to be described. It is convenient to have the bath for holding the tubes made in two separate portions, K and K'. T h e box K can be conveniently made of galvanized iron with legs, U and U', of any convenient length, so that a lamp can be placed underneath the box. T h e liquid to be used in the bath i m y be water or other substance of different boiling point, and should stand at the height represented by the line W. T h e box has a false bottom represented by the dotted line 0, with circular perforations to receive the bottom of the extraction tubes, as indicated. Both sides of this box are conveniently made of glass or mica so that the operator can see the progress of the evaporation of the solvent. T h i s box K' is to rest lightly on K but is not fastened to it in any way. I t is also conveniently made with one or both sides of glass or mica. T h e bottom of the box carries rubber diaphragms, perforated to receive the extraction tubes, through
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I11P R OTIC I) 1: STK A C T 10s ;I P 1'X K .ITUS
which the tubes pass \rater-tight. T h e p l m of the bottom is showri in figure H ' N' G ' . The rubber diapliragiiis are lieltl by tn-o brass rings fasteiietl together 1)y sninil liolts. Oiie of these rings is placed beloiv the perforated hottoix and oiie above. The perforation of the rubber
