& W. Johnson— Apparatus for 



ART. XXII.— Apparatus for rpio H rit->f>n- Fot-xtrm'Mou ; On the 

 Composition of tin Sn;, Point <J„ ,/, Com/motion <>r Huh 

 Fodder; by S. W. Johnson.— Contribution* from tin Shrftithl 

 Laboratory of Yale College* No. XLIII. 



I. Apparatus for quantitative Fat-extraction. 

 The apparatus consists of a glass tube A, off to £ in. bore 

 and 6 to 7 in. long, narrowed at bottom to a bore of \ in., and 

 there fitted by a cork to a flask C, of 80 c. c. capacity, and con- 

 nected above by a cork with a reversed Lie- 

 big's condenser 1). Within A a similar but 

 smaller tube B is maintained free from the 

 sides of the larger tube, either by three knobs 

 of glass fused upon it where it begins to nar- 

 row, by a support of platinum foil as in the 

 figure, or by suspension with help of a wire 

 looped around the upper part of B and a 

 hook depending from the cork above it. B 

 is closed below either by a plug of cotton or 

 asbestus or else bv a disk of filter paper sup- 

 ported by one of muslin tied over its narrow 

 and slightly flanged end. The substance to 

 be extracted is introduced into B, 50 c. c. of 

 ether or other solvent are placed in the flask 

 and heat is applied to boil the liquid, i" Its 

 vapor passes into the condenser, and there 

 liquefies ; the liquid drops continuously upon, 

 and percolates the contents of B. carrying 

 into any dissolved matters, whence it rises 

 again as vapor to be again condensed and 

 repeat the solvent action^ 



The cooling must be effectual and the heat 

 applied to the flask just sufficient to main- 

 tain a regular circulation of the solvent. B 

 may be weighed with its contents, after clos- 

 ing the end by means of corks or rubber 

 caps. To dn ,ts font, nts it may be connected at one end by 

 mean', of a perforated stopper and tube to an appa i - 



< .gen, at the other by a rubber tube several 

 « « n be heated 



I position in a bath of boiling water, 

 iry gas is transmitted. The los 



byi, 



while a sic 



weight of B and its dried c 



amount of oil extracted mor 



„ the 



