158 



HATCH EXPERIMENT STATION. 



[Jan. 



simply as a protection against adulteration, the results of 

 which in no way affect the price of milk or cream to either 

 the producer or consumer, shall be considered exempt from 

 the law. 



2. All parties employing the Babcock or similar test (as 

 described in section 4) for the purpose of measuring the 

 butter fat contained in the milk or cream, as a basis for 

 determining or fixing the value of such milk or cream (to 

 either producer or purchaser), shall be considered subject 

 to the requirements of the law. 



The law practically resolves itself into three sections : 

 (1) the testing of glassware for accuracy of graduation ; (2) 

 the examination of candidates for proficiency in operating 

 the test ; (3) the inspection of Babcock machines. 



Inspection of Glassware. — The scale on the neck of the 

 cream, whole and skim milk bottles is tested for accuracy 

 of graduation by the mercury method, as described by Far- 

 rington & Woll in their work entitled "Testing milk and 

 its products." Pipettes and acid measures are tested for 

 accuracy by carefully measuring the amount of water they 

 deliver. The following limits of error were adopted : — 



Capacity. 



Single 

 Graduation. 



Limit 

 of Error. 



Cream bottles, Connecticut, 



Cream bottles, Connecticut, 



Cream bottles, Bartlett, 



Milk bottles, common, 



Milk bottles, Ohlsson, . 



Milk bottles, Wagner, . 



Skim milk bottles, double quant 



Skim milk bottles, Ohlsson, 



Skim milk bottles, improved Ohlsson, 



Skim milk bottles, Wagner, 



Skim milk bottles, Improved Wagner, 



ity, 



Pipettes, cream, 

 Pipettes, milk, 

 Acid measures, 



Per Cent. 

 30-35-40 



50 



25 



10 



. 5 



8 



2.00 



.50 



.25 



.50 



.25 



Cubic 



Centimetre. 



18.00 



17. CO 



17.50 



Per Cent. 

 .50 



1.00 



.20 



.20 



.10 



.10 



.10 



.05 



.01 



.05 



.01 



Cubic 



Centimetre. 



Per Cent. 

 .50 



.50 



.20 



.20 



.10 



.10 



.10 



.02 



.01 



.02 



.10 



Cubic 



Centimetre. 



.10 



.10 



.20 



