158 METHODS OF ANALYSIS. 



(d) DETECTION OF ACETANILID.O 



Boil the acetanilid, obtained as described under (a), in a small beaker for 

 two or three minutes with 2 to 3 cc of concentrated hydrochloric acid, cool, 

 divide into three portions, and test in small tubes (4 to 5 mm inside diameter), 

 as follows : 



BITSEBT'S TESTS. 



To one portion add carefully 1 to 3 drops of a solution of chlorinated lime 

 (1:200) in such a manner that the two solutions do not mix. A beautiful 

 blue color formed at the juncture of the two liquids indicates acetanilid. 



(2) To another portion add a small drop -of potassium permanganate solu- 

 tion. A clear green color is formed if any appreciable amount of acetanilid is 

 present. 



(3) Mix the third portion with a small drop of 3 per cent chromic acid solu- 

 tion. Acetanilid gives a yellow-green solution, changing to dark green on 

 standing five minutes, and forming a dark blue precipitate on addition of a 

 drop of caustic potash solution. 



These tests are conclusive only when taken in conjunction with the melting 

 point. 



5. Total Solids. 



Weigh about 25 grams of the extract into a large, flat-bottomed dish whicn 

 contains enough freshly ignited asbestos to absorb it ; dry for twenty to twenty- 

 four hours in a water- jacketed oven. 



6. Determination of Ash. 



Evaporate 10 grams of the extract and determine the ash as directed under 

 " VI. General Methods," page 38. 



7. Examination of Ash. 



Proceed as directed under " III. Inorganic Plant Constituents," page 21, or 

 under " XXVI. Baking Powder, etc.," page 177. 



8. Sucrose. 

 Determine as directed under " XIII. Wine," on page 87, under section 17. 



9. Detection of Vanilla Resins, 

 (a) GENEBAL DISCUSSION. 



The most important fragrant principle of the vanilla bean and of true vanil 

 extract is vanillin, or by droxymethoxy benzole aldehyde. It is not, however, 

 only fragrant or valuable constituent of the vanilla bean and true vanill 

 extracts. The artificial vanillin is identical with the vanillin contained in tl 

 vanilla bean, but the bean also contains, among the many extractive matte 

 which enter into the food value and fragrance of the extract, certain resli 

 which can be identified with certainty by a numfter of reactions. If negath 

 results are obtained by these tests, it is evident that the extract was not ma< 

 from true vanilla beans. 



Vanilla beans contain from 4 to 11 per cent of these resins, which vary 

 dark red to brown in color and furnish about one-half of the color of tl 



Pharm. Ztg., 1888, 88: 383; Abs. Zts. anal. Chem., 1888, 27: 667. 



