121 



It consists of a graduated burette with a 

 pinch cock, a 50 cc pipette, a glass tum- 

 bler and a glass rod. The test depends 

 on the property of a certain chemical 

 called phenolpthalein, labelled "indi- 

 cator," which, while white when in acid 

 solution, turns pink in an alkaline solu- 

 tion. Fifty cubic centimeters of milk 

 are measured into the tumbler with the 

 pipette and four or five drops of the 

 indicator added. Meanwhile an alka- 

 line solution (called neutralizer) (1-10 

 normal) is filled into the burette to the 

 O mark and then run into the milk, a 

 little at a time, while stirring until the 

 pink color shows permanently. The 

 number of cubic centimeters normal 

 used is read off on the burette and in- 

 dicates the acidity. 



Prof. Farrington adapted the dry 

 alkaline tablets colored red and a very 

 simple and quick system for testing the 

 milk at the weigh can in order to reject 

 that which is too sour. Full descrip- 

 tion is given in his book on "Milk Test- Fie ' 

 ing/'' which should be found in every creamery and every milk 

 shipping station, just as Prof. Russell's Dairy Bacteriology 

 should be found in the library of every milk producer. 



* The Chr. Hansen's Laboratory, of Little Falls, N. Y., sug- 

 gested in their direction for use of their Lactic Ferment to use 

 lime water as a neutralizer, and it seems to be approved of 

 by the Scandinavian scientists. It has certainly a great many 

 advantages both as to convenience and costs. The "Neutral- 

 izer" sold for Mann's test, even if correct, when made is liable 

 to lose strength by exposure to air (like all others), and hence 

 it will not do to buy it in large quantities, and the express 

 increases the cost very much. If lime water is fairly reliable 

 there is no reason why every creamery or milk shipping sta- 

 tion manager should not prepare their own. Dr. E. N. Eaton, 

 whose opinion I have asked, reports: 



