8 THE COMPOSITION OF BED PEPPERS. 



ETHER EXTRACT, VOLATILE AND NONVOLATILE. 



Determine as directed on page 163, under 9, Bureau of Chemistry, 

 Bulletin 107, Revised, except that the extraction is carried on for 

 24 hours instead of 16. 



CRUDE FIBER. 



Determine as directed on page 56, under 11, Bureau of Chemistry, 

 Bulletin 107, Revised. 



EXAMINATION OF THE OIL. (SEEKER'S METHOD.) 



Preparation. rSpread 5 grams of paprika on a watch crystal and 

 dry over sulphuric acid for at least 12 hours. Measure 250 cc of 

 anhydrous alcohol-free ether, prepared as directed on page 39 of Bul- 

 letin 107, Revised, into a graduated flask on which the mark is situ- 

 ated near the lower end of the neck, and brush the paprika into it. 

 Place a mark on the neck of the flask at the point where the meniscus 

 is and allow to stand for 1 hour, shaking at 20-minute intervals during 

 that time. Bring the meniscus back to the mark upon the neck, 

 either by cooling the flask and contents if the level has risen, or by 

 adding absolute ether if it has fallen. Let the solid particles settle, 

 pipette off 100 cc of the supernatant liquid, and filter this through 

 an 1 1 cm closely woven paper into a tared, air-dry 250 cc Erlenmeyer 

 flask (glass stoppered) that has been counterpoised against a similar 

 flask. Wash the paper with a little absolute ether and then distill 

 off the solvent, removing the flask from the bath as soon as the ether 

 ceases to come over. Lay the flask on its side in a water oven and 

 heat for 30 minutes; cool the open flask for at least 30 minutes in the 

 air and weigh. Repeat this heating and weighing until the weight is 

 constant to within 1 mg, two heatings usually being sufficient. Note 

 the percentage of ether extract obtained. 



This method gives a lower amount of nonvolatile ether extract than 

 the continuous extraction method; the average results as shown in 

 Tables 3 and 7 give from 1 to 2 per cent lower ether extract by this 

 method. 



lodin number. Dissolve the ether extract in the flask with 10 cc 

 of chloroform, and when the solution is complete add 30 cc of Hanus 

 solution, following the method on page 137, Bulletin 107, Revised, and 

 allowing 30 minutes for the halogen absorption. Note the iodin num- 

 ber of the ether extract. A second aliquot of 100 cc, measured out 

 immediately after the first, may be taken from the ether extract in 

 the graduated flask in order to run a duplicate determination of the 

 iodin number. If it is found necessary to heat the ether extract 

 longer than one and one-half hours to obtain constant weight, or if 

 the extract is decolorized on heating, the determination should be 

 rejected and a new one made, using freshly purified ether. 



