714 EXPEEIMENT STATION" RECOED. 



the acetyl number of fats, it is pointed out that the acetyl numbei' of a fat and 

 of the insoluble acids affords valuable information relative to the nature and 

 the quality of the product under examination, and a short and simple volumet- 

 ric method is proposed which is free of many of the objectionable features of 

 the Benedikt and Ulzer and Lewkowitsch methods. 



" The development of the method extended over a period of several years 

 and finally resolved into an adaptation of several well-known processes. 

 Ceresin is used to solidify the acetylated fat so that it may be washed by de- 

 cantation as in the determination of insoluble acids. The saponification number 

 of the acetylated fat is determined by the same process as that of the original 

 fat and the difference measures the amount of acetyl that has been assimilated." 



A gravimetric method similar to the one described by Lewkowitsch is also 

 given, but it is stated that it has not received sufficient study to warrant the 

 drawing of definite conclusions. 



The acetyl number in this work is defined as the number of milligrams of 

 potassium hydroxid required for the saponification of the acetyl assimilated by 

 one gm. of an oil, fat, or wax on acetylization. The prevalent custom of re- 

 porting the acetyl number on the basis of the acetylated product seems to be 

 without foundation. 



The estimation of citric acid in the presence of certain other acids, L. 

 GowiNG-ScoPES (Analyst, 38 {1913), No. 442, -pp- 12-19, fig. 1; ahs. in Chem. 

 Ztg., 37 {1913), No. 47, p. 480).— The Beau modification of Deniges' method was 

 studied and found unsatisfactory. Instead, a reagent composed of a mixture 

 of mercuric nitrate, manganese nitrate, and nitric acid is recommended. The 

 results obtained by the new method showed a maximum error of only +0.0003 

 and —0.0004 per cent. The presence of malic and lactic acids influences the 

 results, but tartaric and succinic acids do not. 



The use of sodium citrate for the determination of reverted phosphoric 

 acid, A. W. Boswokth {New York State Sta. Tech. Bui. 34 {1914), pp. 10-12; 

 Jour. Indus, mid Engin. Chem., 6 {1914), No. 3, pp. 227, 228). — Previously noted 

 from another source (E. S. R.. 29, p. 795). 



A new method for determining nicotin in the presence of ammonia, R. 

 Spallino {Gaz. Chim. Ital, 43 {1913), II, No. 4, pp. ^.93-500).— This method is 

 based on the fact that nicotin behaves toward picric acid as a diacid base in 

 aqueous solutions and as a monoacid base in alcoholic solutions. 



The method is as follows : From 1.5 to 3.5 gm. of tobacco is mixed with milk 

 of magnesia and distilled with steam. The vapors are then collected in from 

 50 to 100 cc. of an aqueous solution of picric acid. After from 600 to 700 

 cc. of distillate is obtained it is diluted with 1 liter of alcohol and divided into 

 two portions, which are separately evaporated to dryness. The residue from one 

 of the portions is dissolved in alcohol and titrated with half-normal barium hy- 

 droxid solution against lacmoid. The other residue is then treated with water, 

 made up to 100 cc. -with water, filtered, and 75 cc. of the filtrate titrated with half- 

 normal barium hydroxid. The difference between the titration of the alcoholic 

 and aqueous residue solutions, when multiplied by 0.0081, gives the amount of 

 nicotin present in grams. 



Estimation of nicotin in the form of silicotungstate, R. Spallino {Gaz. 

 Chim. Ital., 43 {1913), II, No. 4, pp. 482-486) .—The author states that the 

 gravimetric determination of nicotin as silicotungstate gives good results if 

 the factor 0.1139 is used for calculating the nicotin content. If the procedure 

 of drying, as suggested by Chapin (E. S. R., 25, p. 16), is followed, the results 

 are discordant. 



About the occurrence of nicotinic acid (m-pyridin carbonic acid) in rice 

 bran, U. Suzuki and S. Matsunaga (Jour. Col. Agr. Imp. Univ. Tokyo, 5 



