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COMPARATIVE STUDIES WITH COVERED MILK PAILS 93 
the quality of the milk to pass it through a strainer. This 
is true of the milk produced under highly sanitary conditions 
where but little external contamination gets into the milk. 
Straining milk of this sort through a cloth strainer normally 
lessens its keeping quality. In this way the value of the milk 
may be actually injured by the straining process. This being 
the case it is evidently undesirable to pass milk through a 
strainer if it has been produced under such good conditions that 
there is no insoluble dirt which can be strained out. With 
this fact in mind it was thought desirable to make tests with 
the different covered pdils to determine whether or not the 
use of a strainer was desirable. Such tests have been made 
with several of the more important pails now in use. 
THE STADTMUELLER COVERED PAIL WITH AND WITHOUT 
STRAINER. 
A series of tests to determine the effect of using a strainer 
upon the Stadtmueller pail has been made and the results are 

Fic. 33—Photograph showing the. Stadtmueller covered pail without 
strainer.. Compare with Fig. 27. 
