1918] AGRICULTURAL CHEMISTRY AGROTECHNY. 315 



In a modiried tube from 4 to 4.5 gm. of evaporated milk or from 7 to 7.5 gm. 

 of a 40 per cent emulsion of sweetened condensed milli are diluted to a volume 

 of 9 cc. with water and, after mixing with 1.5 cc. of concentrated ammonium 

 hydroxid, 15 cc. of 95 per cent alcohol is added and the whole mixed again. 

 The mixture is then shaken vigorously for 2 minutes with 50 cc. of mixture 1. 

 After standing for 10 minutes the fats are filtered through a 4-cm. Dreverhoff 

 No. 86 fat-free filter paper into a 100-cc. Erlenmeyer flask, previously dried 

 and weighed. The tip of the spigot of the modified tube and the paper are 

 washed with a few cubic centimeters of mixture 1, and the funnel with the 

 paper set aside for future use. The ethers are distilled on a hot plate, using 

 cork stoppers covered with tin foil for connecting with the condensers, until ap- 

 proximately 4 cc. remains. The recovered ethers are returned to bottle 1 and 

 the liquid in the tube mixed with 3 cc. of glacial acetic acid. The tube, im- 

 mersed in water at 60-65° C. by a wire so that the tip of the spigot is just 

 above the water, is heated to 80° in about 10 minutes. The tube is removed, 

 cooled in running water, and shaken vigorously for about 2 minutes with 50 cc. 

 of mixture 2. After standing a few minutes the ethers are filtered through the 

 reserved filter paper into an unweighed 100-cc. Erlenmeyer flask, distilled, and 

 returned to bottle 2. 



This extraction is repeated with 50 cc. of mixture 2, and the ethers filtered 

 into the same unweighed flask. The tip of the spigot and filter paper are 

 washed with mixture 2 and the ethers distilled as before. The flask is freed 

 from the residual liquid and acetic acid vapors and dried completely by heat- 

 ing on a steam bath while applying suction. The fat is then dissolved with 25 

 cc. of petroleum ether, using small quantities at a time, and filtered through the 

 same filter as before into the weighed flask containing the first extract. The 

 petroleum ether is recovered, and the fat dried at 100° to constant weight and 

 weighed. 



From some work on the Harding-Parkin method (E. S. R., 29, p. 507) it is con- 

 cluded that the higher results obtained with this method are due to the use of 

 rubber stoppers in contact with the solvents. 



Analytical data obtained in the study show that the error of the Rose- 

 Gottlieb method as applied to condensed milk is small, the average being about 

 0.04 per cent. The method may also give low results when applied to milk 

 powder or cream. This error may be corrected by an extraction in the pres- 

 ence of acetic acid. The method described is considered to extract free fatty 

 acids and more completely separate the fat from the protein, recovering a 

 trace of fat not obtained by alkaline extraction. The economy in the use of 

 solvents is also noted. 



Outline for the analysis of sugar products, H. Lajoux and L. Ronnet {Jour. 

 Phartn. et Chim., 7. ser., 16 {1911), No. 7, pp. 199-204). — The authors submit an 

 outline for the examination of sirups, confections, honeys, etc., in tabular form 

 which is deemed especially useful for routine examinations. Brief notes on 

 the details of the various procedures are also given. 



A method for the determination of alcohol, C. J. Haines and J. W. Maeden 

 {Jour. Indus, and Engin. Chem., 9 {1917), No. 12, pp. 1126, 1127).— The follow- 

 ing modified method is described : 



Ten cc. of the alcoholic solution at 15.6° C. is measured into graduated tubes 

 of 15 cc. capacity and potassium fluorid added until the volume reads 13 cc. A 

 small crystal of malachite green is dropped in, which serves to color the alcohol 

 layer so that the volume can be easily read. Other substances could be used, 

 bat the malachite green has been found to be very satisfactory. The tube is 

 then closed with a tight-fitting stopper and shaken vigorously for about 2 

 minutes. If the potassium fluorid is dry, the solution warms up but when 



