714 EXPEEIMENT STATION EECORD. 



are not destroyed by phenolase or by peroxidase plus hydrogen peroxid, the 

 following method is employed for noting esterase activity : 



One gm. of the material to be tested is rubbed up with quartz sand, and 5 

 drops of glycerol are incorporated with 500 cc. of lukewarm water and strained 

 through a cloth. Ten cc. of the emulsion-like cloudy fluid is mixed in a test 

 tube with 0.1 gm. of guaiacol carbonate and a few drops of toluol and placed in 

 an incubator at 40° 0. At the same time a control test is made under similar 

 conditions but the emulsion added is previously heated to the boiling point. 

 After 5 to 30 minutes both samples are heated rapidly to the boiling point for the 

 purpose of destroying catalase and perhydrase, then cooled, and 1 drop of 

 peroxidase and 1 drop of a 3 per cent solution of hydrogen peroxid are added. 

 According to the quantity of esterases present a more or less brownish red 

 coloration ensues. The control remains colorless. 



A method is also given wherewith one can follow the quantitative cleavage 

 of guaiacol carbonate. 



International review of the literature of food, its composition, analysis, 

 and adulteration, for the year 1911, A. J. J. Vande\'elde {Repert. Internat. 

 Comp., Anal, et Falsif. Denrees Aliment., 12 (1911), pp. 88-\-10). — ^A con- 

 tinuation of the woi-k previously noted (E. S. R., 29, p. 360). 



The decomposition of protein substances of milk through, the action of 

 lactic ferments, W. C. De Gbaaff and Mlle. A. Schaap {Ann. Falsif., 6 

 (191S), No. 62, pp. 639-645). — With the aid of the method previously noted 

 (E. S. R.., 31, p. 413) it was found that the aldehyde index of buttermilk was 

 much greater than that of fresh milk. This is due to the decomposition of the 

 protein substances of milk by the microscopic flora which develop and cause 

 proteolysis. The cocci and bacilli producing lactic acid are not the only micro- 

 organisms which peptonize. 



A rapid method for casein in milk, W. O. Walker (Jour. Indus, and Engin. 

 Chem., 6 (1914), No. //, p. 356).— An addition to the article noted (E. S. R., 32, 

 p. 413). " Since the above work was completed it has been found that beechwood 

 creosote serves as an admirable preservative for milk. When added in the 

 proportion of 5 cc. to 1 pt. of milk, the latter keeps in good condition for 

 several months if placed in the dark. The preservative does not interfere with 

 the casein test, nor the Babcock fat test, provided only one-half the usual amount 

 of sulphuric acid is used. 



The judgment of adulterated milk, R. Eichloff and H. Bleckmann 

 (Milchiv. Zenibl., 43 (1914), A^o. 24, pp. 561-569, fig. i).— This investigation was 

 conducted for the purpose of determining to what extent the addition of potas- 

 sium bichromate employed for preserving milk samples affects the specific 

 gravity, total solids, fat-free solids, and percentage of fat. 



It is concluded that with milk samples preserved with 0.1 per cent of potas- 

 sium bichromate the total solids and fat can be determined with accuracy by 

 the gravimetric method. The results obtained with Fleishmann's formula were 

 unsatisfactory, but incorrect results were also obtained in the case of an 

 unpreserved sample. 



A balance with which one can make a rapid estimation of total solids is shown 

 and described. 



Detecting milk adulteration by the removal of cream, L. Van Dam (Ann. 

 Falsif., 7 (1914), No. 66, pp. 187-195; abs. in Ztschr. Angcw. Chem., 27 (1914), 

 No. 53, Referatenteil, p. 417). — It is deemed possible to detect skimmed milk by 

 determining the ratio of casein to fat in the sample. The casein can be deter- 

 mined according to Cornalba's method and the fats according to the Rose- 

 Gottlieb method. In the 144 samples of milk examined the ratio of casein to 



