384 EXPERIMENT STATION RECORD. 



samples were taken in August and September and in March and April. 

 The range and the average composition of the 130 samples of milk 

 were as follows: 



Composition of milk sold hi Giessen. 



The fat content was 3.5 per cent or over in more than two thirds of 

 the cases and 4 per cent or over in 35 per cent of the cases. On the 

 basis of the investigation, a specific gravity of from 1.028 to 1.0315 and 

 a fat content of 3 per cent are recommended as the milk standard for 

 whole milk for the city. 



Abstract of the report of the experiment station and school 

 at Kleinhof-Tapiau for 1897-98 {Milch Ztg.,27 (1898), No. 32, pp. 

 500-502). — Among other things the report contains the results of a test 

 of Wollny's refractometer and the Gerber and Babcock milk tests. 

 The results of the examination of the milk of the Kleinhof-Tapiau herd 

 from 1889 to 1897 (K. S. K., 7, p. 50) are briefly discussed in the abstract, 

 and a summary is given for the year ending September 30, 1897. Data 

 are given as to the yield of different kinds of cheese from whole milk 

 and from skim milk, the losses in ripening different kinds of cheese, etc. 



A method for distinguishing pasteurized and unpasteurized 

 milk, V. Stokch (40. Bericht des Versuchslaboratoriums der Kgl. Veter- 

 inar- und Landbauhochschule. ■ Copenhagen: A. Bang, 1898; abs.in Milch 

 Ztg., 27 (1898), No. 24, pp. 374, 375). — In Denmark the laws for the sup- 

 pression of tuberculosis forbids the selling of skim milk or buttermilk 

 which has not been heated to at least 85° C. It was for the execution 

 of this law that Professor Storch devised his method. The method is 

 based upon Babcock's discovery that the fibrin of milk decomposes 

 hydrogen peroxid, that cream is more active in this respect than whole 

 milk, that skim milk is less active, and furthermore that milk heated to 

 100° loses this' property. Storch found that milk retained its property 

 of reducing hydrogen peroxid up to 79° C. As an indicator of the reduc- 

 tion he uses paraphenylendiamin. 



The hydrogen peroxid solution is made by diluting the commercial 

 article (when it contains 1 per cent of the material) with 5 times its 

 volume of water and adding 1 cc. of concentrated sulphuric acid per 

 liter. In making the test a teaspoonful of the milk (cream or whey) is 

 shaken in a test tube with a drop of the peroxid solution and 2 drops 

 of the paraphenylendiamin solution. If the milk colors immediately 

 (milk or cream, indigo blue; whey, violet red brown) it has not been 

 heated to 78°. 0., and in fact has not been heated at all. If the milk or 

 cream becomes grayish blue immediately or in half a minute, the iudi- 



