508 EXPERIMENT STATION RECORD. (Vol.31 



minutes. The fat column is then measured as usual and the reading multiplied 

 by four. 



For dried milk from 5 to 6 cc. portions of concentrated sulphuric acid are 

 added to a 4.5-gm. sample until a dark brown color develops. The sulphuric- 

 nitric acid mixture u.<^ed foe malted milk is th«n added, 0.5 cc. at a time, with 

 thorough agitation, until a light red color results. The material is then im- 

 mersed in boiling water until the dark brown color returns, more of the acid 

 mixture added until the light color is produced, and again immersed in boiling 

 water until the dark brown color reappears. The procedure is then carried out 

 the same as for malted milk. 



Experimental data submitted indicate uniformly higher results with the pro- 

 posed procedure than with the Rose-Gottlieb method. Directions for the prepara- 

 tion of the samples of the various products, together with a graphical chart 

 showing Ihe variation in the fat content of 75 samjiles of ice cream, are included. 



The determination of water soluble fatty acids in butter and other fats, 

 M. Kauifman {Cliem. Weclcbl., U {1917), No. 16, pp. 56-J-367 ) .— The following 

 procedure, which is deemed to yield accurate results and to be much simpler 

 than the usual procedure, is described : 



One gm. of the sample is treated in a 200-cc. flask with 50 cc. of 13/100-normal 

 alcoholic potash solution. After saponification under a reflux condenser, a small 

 amount of water at about 90° C. and 50 cc. of 15/l(X)-normal sulfihuric acid 

 are added. After cooling, the volume is made up to 200 cc, the liquid filtereil. 

 and 100 cc. of the filtrate titrated with tenth-normal alkali, using phenol- 

 phthalein as indicator. An excess of acid .should be present to insure complete 

 liberation of all the fatty acids and a proper correction for the amount added 

 made. 



Analytical data subniittwl indicate the accuracy of the procedure. 



The correction required in applying the Babcock formula to the estimation 

 of total solids in evaporated milk, O. L. Evenson (Jour. Indus, and Hngin. 

 Chctn., 9 (1917), No. 5, pp. ^i^9-50i).— Experimental data submitted show that 

 the Babcock formula (E. S. R., 8, p. 721) can not be applied directly to the 

 determination of total solids in evaporated milk at either 5° C. or at 37 to 40* 

 when exact results are desired. The formula 



^^L—O^j 2xpercentagc of fat 



Is submitted for obtaining results which are comparal)le with those obtained 

 with the r.abcock forn)ula on whole milk cooled to its maxinmm specific gravity, 

 and the formula 



T= ^~^'^ -fl.2X percentage of fat 



for milk kept at 37 to 40° for 1.5 hours, or until rhere !s no further change 

 in the siiecific gravity. 



The analysis of desiccated milk. — Determination of moisture and fat, C 

 PoiuHEU (.iHH. Falsi/., 9 (1916), No. 97-9S, pp. J,50-Jt56).— The best proce<lure 

 for the determination of moisture was found to be desiccation over pliosphorus 

 pentoxid for 48 hours, or 72 hours If necessary. Drying over sulphuric acid 

 was found not to be satisfactory, and drying over calcium chlorid to be very 

 slow. Ordinary drying in a steam oven caused a brown coloration In the 

 material and an apparent change in some of its constituents. 



The K<ise-Gottlieb procedure was found to be entirely satisfactory for the 

 determination of fat. Direct extraction with ether, however, consistently 

 yielded low results. 



The index of refraction of olive oil in relation to acidity and rancidity, 

 A. CUTOLO (Stuz. Spcr. Agr. Ital., 1,9 (1916), No. 7-8. pp. S77-.iS7).—Vati\ rela- 



