98 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 



of fusel oil. Treat in the same manner and at the same time a solution of 30 per 

 cent (by volume) aldehyde-free alcohol containing 0.05 grams of acetic aldehyde per 

 liter. After two minutes, match the colors of the two mixtures by dilution of the 

 stronger with 30 per cent aldehyde-free alcohol, or by means of a colorimeter, and 

 express the result as acetic aldehyde. 



9. DETERMINATION OF ETHEREAL SALTS. 



After the determination of the volatile acids the neutralized distillate is transferred 

 to a flask connected with a reflux condenser, treated with 25 cc of tenth normal 

 sodium hydroxid, and boiled one-half hour. The flask and contents are then 

 cooled, 25 cc of decinormal hydrochloric acid added, and the excess of acid titrated 

 with sodium hydroxid, using phenolphtalein as indicator. The number of cubic 

 centimeters of decinormal alkali used in this titration, multiplied by 0.0088, is 

 equal to the weight in grams of ethereal salts (calculated as ethyl acetate) in the 

 volume of liquor taken for the determination. 



10. DETERMINATION OF FURFUROL. a 



Treat 5 cc with 5 drops of colorless anilin and 8 drops of acetic acid. After fifteen 

 minutes, compare colorometrically with 5 cc of a solution containing 0.05 grams of 

 furfurol per liter which has been subjected to the same treatment. 



11. DETERMINATION OF COLORING MATTER. 



Proceed as directed under methods for the detection of coloring matter, (p. 111). 

 For the detection of caramel use the method of Crampton and Simons, b which 

 depends on the insolubility of caramel in ether. Evaporate 50 cc of the sample 

 nearly to dryness on the water bath, wash into a 50-cc flask, add 25 cc of absolute 

 alcohol, cool to a definite temperature, and dilute to mark with water. Transfer 

 25 cc to an apparatus of the general description of Brom well's fusel-oil apparatus 

 (page 97), but graduated so that the lower bulb holds 25 cc to a definite mark on 

 the stem, which may be of larger tare than in Brom well's apparatus. Add 50 cc of 

 ether and shake at intervals for half an hour, let settle, and siphon water through 

 the lower tube until the aqueous layer reaches the 25-cc mark. Mix the whole, 

 remove the aqueous layer, and compare by means of a tintometer with the 25 cc 

 of the solution which were 'not treated with ether. Express the amount of color 

 removed on the percentage basis. 



XT. BAKING POWDERS AND BAKING POWDER CHEMICALS. 



By A. L. WINTON, 

 CJiemist of State Experiment Station, New Haven, Conn. 



All the processes hereafter described, except determination <>f acidity, may be 

 employed in the analysis of baking powders, and all the processes, except deter- 

 mination of carbonic acid, in the analysis of cream of tartar and its substitutes. The 

 sample under examination is entirely removed from the package, carefully mixed, 

 and passed through a sieve without grinding. 



1. DETERMINATION OF TOTAL CARBON DIOXLD. C 



This determination is made by the absorption method, and any apparatus may 

 be employed which gives accurate results when checked with pure calcite. What- 

 ever apparatus is chosen the tubes and materials used for absorbing and drying the 

 carbon dioxid may be varied according to the preference of the analyst. Those 



"Windisch. Forsch. uber Lebens., 1897, 4, 369. "See Appendix, p. 156. 



11 Jour. Am. Chem. Soc., 1890, 22, 810. 



