DAIRY FARMING DAIRYING. 385 



cation is that it bas been beated to 70 or 80°, and if it retains its orig- 

 inal white color or is colored only slightly violet red it bas been heated 

 to more than 80°. 



In testing sour buttermilk a teaspoonful is neutralized with lime- 

 water and tben the peroxid and indicator added. If the mixture turns 

 blue tbe indication is tbat the cream from which the buttermilk origi- 

 nated was not beated to 80° C, but if no color appears it has been 

 heated to 80° or more. 



In testing butter about 25 gm. is melted in warm water, the clear 

 butter fat poured off, and the milky residue adulterated with a like 

 volume of water. The mixture is then tested in the same way as milk. 

 If a blue color appears tbe conclusion is that the cream from which tbe 

 butter was made was not heated to 80° C, but if there is no color or a 

 weak violet brown color the butter was made from pasteurized cream. 



Accompanying Storch's paper is a colored plate showing the colors 

 of the reactions with pasteurized and unpasteurized milk, cream, skim 

 milk, and whey. 



A new method of preserving milk. H. De Lavallee (Abs. in 

 Milch Ztg., 27 (1898), No. 30, p. 472).— Directly after milking the milk is 

 placed in a cooled vessel and treated to pure carbonic acid under pres- 

 sure of 5 to G atmospheres for 4 or 5 hours. Following tins it is treated 

 to oxygen at 5 atmospheres for 5 hours. This treatment kills all the 

 aerobic and anaerobic bacteria. The milk is transported in vessels 

 containing oxygen under "2 atmospberes of pressure. Tbese vessels 

 may be made in the form of siphons. Milk treated in this way is said 

 to retain all the properties of fresh milk and can be guaranteed to be 

 entirely free from all diseased germs. 



Factory tests for milk, S. M. Babcock, H. L. Eussell, and J. W. 

 Decker ( Wisconsin Sta. Bui. 67, pp. 20, Jigs. 6, pi. 1). — The statement 

 is made at tbe outset that " every cheese factory, whether conducted 

 upon the relative value plan or not, should be equipped with suitable 

 apparatus for determining tbe cheese value of milk, and no one should 

 be considered competent to manage a factory unless he knows how to 

 use such apparatus." The use of the milk tester and lactometer for 

 determining the composition of milk is described, and attention is 

 called to the fact that the cleanliness and bacteriological condition of 

 tbe milk, which are frequently overlooked, are matters of no less 

 importance in cheese making than the composition. 



'•If the milk contains micro-organisms that are capable of decomposing any of 

 the cheese-producing substances or is impregnated with taints or obnoxious flavors 

 that are absorbed from the animal or after the milk is drawn, tben its theoretical 

 value as based upon the nutritive wortb of its various elements is diminished to a 

 greater or less degree by the operation of this second factor. So far tbe value of 

 milk has been entirely determined by its cheese-producing capacity, and the influ- 

 ence of biological factors (bacteria, etc.) upon the character of tbe product bas 

 been ignored. . . . The actual value of any milk may be materially modified by the 

 presence of taints (actual or potential), and to detect tbese is a very necessary 

 and essential part of tbe cheese maker's business." 



