14 



Under heading "i," and following section "( c )?" insert the follow- 

 ing method as provisional: 



[Note by the Editor. This method was not acted upon directly by 

 the association, but its adoption is implied in section U 4, (a)," in which 

 its use is required.] 



(d) RITSERT'S TESTS FOR ACETANILID. 



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 (4-5 mm inside diameter) as follows: 



(1) Indoplienol reaction. 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 solution. 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 solution. 

 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. 



aPharm. Ztg., 1888, 33: 383; Abs. Zts. anal. Chem., 1888, 27: 667. 



Leach and Lythgoe's refractometric method for the detection of 

 methyl alcohol was adopted as a provisional method in the analysis of 

 extracts. 



DETECTION AND DETERMINATION OF METHYL ALCOHOL IN VANILLA EXTRACT (METHOD 

 OF LEACH AND LYTHGOE<*). 



Submit the alcoholic distillate obtained in the determination of alcohol to refrac- 

 tion with the immersion refractometer at exactly 20 C. and note the reading. If on 

 reference to the table the refraction shows the percentage of alcohol agreeing with 

 that obtained from the specific gravity in the regular manner, it may safely be 

 assumed that no methyl alcohol is present. If, however, there is an appreciable 

 amount of methyl alcohol the low refractometer reading will at once indicate the fact. 

 If the absence in the solution of other refractive substances than water and the alco- 

 hols is assured this qualitative test by difference in refraction is conclusive. 



Addition of methyl to ethyl alcohol decreases the refraction in direct proportion to 

 the amount present; hence the quantitative calculation is readily made by interpola- 

 tion in the table, using the figures for pure ethyl and methyl alcohol of the same alco- 

 holic strength as the sample. 



Example: Suppose the distillate from a vanilla extract made up to the original vol- 

 ume of the measured portion taken for the alcohol determination has a specific 

 gravity of 0.97350, corresponding to 18.38 per cent alcohol by weight, and has a 

 refraction of 35.8 on the immersion refractometer at 20. By interpolation in the 

 refractometer table the readings of ethyl and methyl alcohol corresponding to 18.38 

 per centalcohol are 47.2 and 25.4, respectively, the difference being 21.8; 47.235.8= 

 11.4; (11.4--21.8) 100=52.3, showing that 52.3 of the alcohol present is methyl, 

 aj. Amer. Chem. Soc., 1905, 27: 964. 



