20 



KANSAS ACADE31Y OF SCIENCE. 



OX A NEW APPARATUS FOR THE CONTINUOUS EXTRACTION OF 

 SOLIDS BY A VOLATILE SOLVENT. 



BY J. T. AVILLARD AND G. H. FAILYER. 



The authors have devised a new form of extraction apjjaratus, which is so satis- 

 factory to them that they think a brief description of it may be of interest to other 

 chemists. It consists of three parts: the flask A, the condenser B, and the perfo- 

 rated tube C. The flask is 14-15 cm. in height, and weighs about 45 grams. The 

 upper part of the neck is ground to fit the condenser, and is 3 cm. in diameter. 



The lower part of the neck 

 contracts suddenly to 2.5 cm. 

 in diameter, thus presenting 

 an annular projection within, 

 which supports the perforat- 

 ed tube. The tube of the con- 

 denser is about 75 cm. long, 

 and has an internal diameter 

 of 8 mm. Near the lower end 

 it is bent at an angle of 60°, 

 and passed upward through 

 a copper tube 3-4 cm. in di- 

 ameter, which is supplied with 

 cold water when in use. The 

 lower end expands into a 

 stopper for the flask, and the 

 extremity is brought nearly 

 to a point to direct the drop- 

 ping of the condensed solvent. 

 Three additional openings are 

 made in the stopper expan- 

 sion to allow the vapor free 

 passage upward. The perfo- 

 rated tube is similar to a short, 

 wide test-tube with the bottom 

 perforated. The lip is notched 

 to give openings for the pas- 

 sage of the vapor. The body 

 of the tube must pass readily 

 through the contraction in the 

 neck of the flask, and at the 

 same time the lip must rest 

 securely on the inner projec- 

 tion. The lower end of the 

 tube may reach within 1.5-2 

 cm. of the bottom of the flask. 

 The mode of using the apparatus is almost obvious. The substance to be treated 

 is confined in the perforated tube between two layers of asbestos, a sufticient amount 

 of the volatile solvent is put into the previously-weighed flask, and the parts are put 

 in place and suitably supported. Upon heating the solvent by means of a water 

 bath the vapor is evolved with any rapidity desired, and passes into the condenser. 

 The condensed solvent flows uninterruptedly down the same tube, drops into the 



A, the flask; B, the condenser tube; C, the perforated tube. 

 B and C are shown somewhat raised from their positions when 

 in use. 



