204 EXPEEIMENT STATION RECORD. 



" In one method there is an indirect determination of the excess of ammonia 

 just past the neutral point by the use of chloroform as soKent. This method 

 is called the ' extraction method.' The second method, like the conductivity 

 method, is a physical method, depending on the great heat evolution when 

 ammonia and citric acid solutions are mixed. This has been called the ' tem- 

 perature method.' " 



Food inspection and analysis, A. E. Leach {'New York and London, 1913, 

 3. ed., rev. and enl, pp. XIX+1001, pis. JfO, figs. 120).— The third edition of 

 this well-known work (E. S. K., 22, p. 411) has been revised and enlarged. 



"Among the new features are improved general methods and apparatus for 

 the determination of moisture, ash, and arsenic, modern apparatus for the 

 Babcock test, processes for the detection of foreign fat in clairy products, 

 methods for the determination of ammonia and acidity in meat, and of sugars 

 in cereal products, correction of Munson and Walker's sugar table, new methods 

 for vinegar analysis (including glycerol determination), schemes for the separa- 

 tion of food colors, a subchapter on formic acid (recently introduced as a 

 preservative), methods for the analysis of lemon and orange oils, a summary of 

 analyses of authentic samples of vanilla extract, and a complete revision of 

 the final chapter on fruit and vegetable products with new sections on tomato 

 catsup, dried fruits, preserves (including maraschino cherries), fruit juices, 

 and nonalcoholic carbonated beverages. In the final chapter are included 

 descriptions of recent methods for the determination of tin, vegetable acids, and 

 habit-formiug drugs, and for the detection of snponin. also microscopical 

 methods for the detection of spoilage. The text of the federal pure food law, 

 as amended during the present year, and of the meat inspection law are added 

 for ready reference as an appendix." 



The detection of phytosterol in mixtures of animal and vegetable fats, 

 R. H. Kerb (U. S. Dept. Agr., Bur. Anim. Indus. Circ. 212, pp. 4)- — Inasmuch 

 as the fat rendered from carcasses of animals fed on cotton-seed products give 

 the Becchi and Halphen reactions for cotton-seed oil, provided the fat has not 

 been heated to a very high temperature, the only certain method with a fat 

 suspected of being adulterated with a vegetable oil is to test it for the presence 

 of phytosterol, which does not appear in the fat of an animal fed on cotton- 

 seed products. 



The principal objection to the usual method for phytosterol is the long time 

 required to carry it out. "As a result of efforts to shorten the method, certain 

 modifications of the details have been introduced, which resulted in the saving 

 of considerable time, and also in avoiding troublesome steps in the process. 

 The principal changes and advantages secured are (1) the employment of a 

 larger sample, which gives a correspondingly larger amount of unsaponifiable 

 material; (2) the extraction of the sample with alcohol, by which means the 

 handling of large amounts of soap is avoided ; (3) the method of extracting the 

 soap with ether, which avoids emulsions and allows the extraction to be accom- 

 plished in a few minutes; and (4) the treatment of the acetates, by means of 

 which it is possible to obtain pure crystals from the second crystallization." 



For the saponification and extraction with ether, the method used by Sal- 

 kowski"^ for the isolation of cholesterol is used. For preparing the acetates 

 " a small amount (3 to 5 cc.) of acetic anhydrid is added to the dry residue in 

 the beaker and heated to boiling over a free flame, the beaker being covered 

 with a watch glass during the process. After a brief boiling — a fevt^ seconds is 

 sufiicient — the flame is removed and the beaker transferred to the steam bath 

 and left there until the acetic anhydrid is driven off." 



» Hoppe-Seylers Ztschr. Physiol. Chem., 57 (1908), No. 5-6, pp. 515-528. 



