8 EXPERIMENT STATION RECORD. 



J90G, pp. XII+2J'i. pi. J. //r/.s. -50).— This l)0()k lias been prepared for the use 

 of dairy students, Imtter makers, fheese makers, miUc inspectors, etc., rather 

 than for the chemist, and the methods described are such as do not necessarily 

 require previous chemical training for their successful operation. The Bab- 

 cock test is very fully considered. Chapters dealing with methods of commercial 

 testing and scoring of butter, cheese, milk, and cream are included. The final 

 chapter gives rules for the various arithmetical calculations frequently neces- 

 sary in testing nulk and milk products, with illustratlA^e examples. 



On the oxidation index of milk, E. Comanducci (Abs. in Chem. Ztfl.. 30 

 (1906), No. .',1. p. .jOJ,). — In determining the oxidation index of milk, which is 

 believed to furnish important information concerning the quality of milk, 10 

 cc. of milk is diluted with water to i liter, 20 cc. of dilute sulphuric acid (1 to 5) 

 added to 10 cc. of this solution, the mixture warmed to GO to 70° C. on the 

 water bath, and decinormal potassium permanganate solution added drop by 

 drop until the appearance of a rose-i'ed color remaining for 5 minutes. The 

 number of cubic centimeters of permanganate solution required for the oxida- 

 tion of 1 cc. of milk, the author calls the oxidation index. As a result of 

 numerous determinations, the following indexes were found: Cows' milk 50 to 

 52, goats' milk 44 to 45, sheep's milk 4.3 to 48, asses' milk 55 to 58, and human 

 milk 53 to GO. The oxidation index of milk diluted with 10 per cent of water 

 was 44, with 50 per cent 25, and with 90 per cent 5. 



Note on a recent paper by R. Steinegger on the " aldehyde figure " of milk, 

 H. D. Richmond and E. li. Miller (Aiiuly-st. 31 (IDOij). Xo. 36',. pp. 22',-226).— 

 Steinegger's method (E. S. R., 17, p. GOG) is considered important because it 

 gives (1) an approximate estimation of the amino-nitrogen. (2) an indirect 

 but easy method for determining proteids, and (3) another easily determined 

 figure capable of furnishing corroborative evidence. 



In mixed milk sodium hydroxid was found to give a mean aldehyde figure 

 of 18.4 and strontium hydroxid, 20.2, expressed in cubic centimeters of normal 

 alkali ]ier liter of milk. Assuming a proportion of casein to albumin in milk 

 of 7:1, the authors find that 1 cc. of tenth normal soda corresponds to 0.0298 

 gm. of the nitrogen of milk and 1 cc. of tenth normal strontia to 0.0271 gm. 

 Steinegger's average was 0.0.303. The maximum, minimum, and average of 

 113 determinations of the aldehyde number were respectively 22.G, 18.1, and 19.9, 

 expressed in cubic centimeters of normal strontia jicr liter of milk. 



The estimation of fat in homogenized milk, II. D. Richmond {AnaUjst, 31 

 {1906), No. 36 !i, pp. 218, 219). — As homogenized milk, prepared by forcing milk 

 under a pressure of from 200 to 400 atmospheres through very small openings, 

 is now an article of commerce, the author sought to ascertain what effect the 

 fine state of division of the fat globules would have upon the determination of 

 fat by ordinary methods. The (iottlieb, kieselguhr, and Werner-Schmid methods 

 gave results in almost jierfect agreement. Good results were also secured by the 

 Gerber method. The Adams method, however, was always low. In the opinion 

 of the author this method, so long a standard, should be discarded in favor of 

 the Gottlieb method, which, for ease and accuracy, is considered the best method 

 for this purpose. 



The analysis of dried milk, II. D. Richmond (Aiiali/st. 31 (1906), No. 36',. 

 pp. 219-22.'i). — Several modificatious of methods used for ordinary milk con- 

 sidered necessary in examining dried millv or milk jiowder are noted and anal- 

 yses of 7 samples are given. 



The Werner-Schmid metliod is considered suitable f(ir determining fat which 

 can not be estimated by direct extraction. In determining milk sugar polari- 

 metrically, 10 gm. of the sample is ground up iu a mortar with sutficient hot 



