712 EXPERIMENT STATION RECORD. 



•• For laboratory use a 20 per cout alcoholic solution, made by diluting the 

 IM) i)er cent conuuercial nitrous ether, is rcx;ouimended. Amyl nitrite may be 

 used, but is disagreeable to work with. Ordinary sweet spirits of niter, which 

 contain about 4 per cent ethyl nitrite, may be used, but will require much longer 

 exposure." 



Botanical micro-chemistry, Gruss (Osterr. Chem. Ztg., IS (J910), No. 23, 

 pp. 289, 290). — This article deals particularly with the guaiac reaction, peroxi- 

 dases, oxidases, oxygenases, diastases, and other plant substances which give 

 the reaction for peroxidase, etc. 



The artificial coloration of foods and condiments, E. Spaeth (Pharm. 

 Zentralhalle, 51 (1910), Nos. 22, pp. J,67-.'tl2; 23, pp. J,9o-501; 2J,, pp. 525-53Jf; 

 25, pp. 557-560; 26, pp. 58^-581; 27, pp. 614-618; 28, pp. 635-638; 41, pp. 935- 

 9JfS; 42, pp. 959-966; 43, pp. 987-991; 44, 1015-1018; 45, pp. 1037-1039; 46, pp. 

 1054-1058; 47, pp. 1076-1079; 48, pp. 1103-1106; 49, pp. 1122-1125).— This is an 

 extensive and critical discussion in regard to the advisability and legality of 

 the ai'tificial coloring of foods, condiments, and beverages. The various colors 

 employed and the methods used for detecting them are considered. The deci- 

 sions of numerous courts are appended in each case. 



Fruit juices and marmalades, E. Spaeth (Ztsclir. Riech u. Oeschmackst., 2 

 {1910), Nos. 14, pp. 155-157 ; 15-16, pp. 165-167).— This is a retrospect of the 

 work done in regard to the judging and analysis of fruit juices and marmalades 

 during the last few years. The more recent methods of analysis are described. 



Composition of Tunisian olive oils, R. Marcille (Ann. Falsif., 3 {1910), 

 No. 23, pp. 372-379; ahs. in Jour. Soc. Chem. Indus., 29 {1910), No. 20, p. 1212).— 

 This reports analyses of 550 samples of Tunis olive oils, representing all of the 

 oils exported from the country from December 1, 190S, to March 31, 1910. 



"The iodin values (Wijs) obtained were: Sfax oils S2.1 to 86.7, Sahel oils 

 81.2 to 84.5, Tunis oils 87 to 92.8. The liquid fatty acids separated from the 

 oils had iodin values varying from -104 to 108. Certain of the oils from the 

 Sfax and Sahel districts yielded color reactions similar to, but not identical 

 with, those given by sesame oil ; no less than 70 per cent of the oils from the 

 Tunis district gave these reactions. The acidity of the oils was extremely 

 low, 85 per cent of the total number of samples showing an acidity of les§ than 

 1 per cent." 



See also a previous note (E. S. R., 22, p. 310). 



Estimation of lecithin in oil, W. Fresenius and L. Grijnhut {Ztschr. 

 Analyt. Chem., 50 {1911), No. 2, pp. 90-106; ahs. in Analyst, 36 {191 L), No. 421, 

 pp. 166, 167).— The method is as follows: 



Fifty gm. of the fixed oil or fat is weighed in a 200 cc. graduated cylinder 

 and agitated for 20 minutes with 1(X) cc. of absolute alcohol, allowed to stand 

 for 1 hour, and the volume of alcohol and oil noted. Seventy-five cc. of the 

 alcoholic solution is then pipetted off for the primary phosphorus determination. 

 The pipette is washed out with absolute alcohol, and the washings added to the 

 graduated cylinder, which is then filled up to the original mark with absolute 

 alcohol. The shaking process is repeated, and after separation of the layers 

 has again taken place another 75 cc. of alcoholic solution is drawn off for a 

 second phosphorus determination. The 2 alcoholic solutions, which are termed 

 ai and a^, are evaporated separately in a platinum dish and the dry residue fused 

 with a mixture of sodium carbonate and nitrate. The phosphoric acid in the 

 fused residue is precipitated with molybdic acid in the usual manner, ignited, 

 dried, and weighed. 



Two preparations of lecithin in oil were found to contain 3.11 and 7.8 per 

 cent of lecithin, respectively. 



