COMPARATIVE STUDIES WITH COVERED MILK PAILS 79 
of the most practical devices used at the present time for 
the purpose of excluding dirt and bacteria from the milk 
during the process of production is some form of covered 
milk pail. The ordinary milk pail is about twelve inches in 
diameter and if it is entirely uncovered it is easy to see that 
a considerable amount of dirt might fall into the milk during 
the process of milking. If, however, this opening can be re- 
duced to a small proportion of the entire area of the pail the 
amount of dirt which could fall in would be correspondingly 
reduced. The demand for some form of covered pail which 
is both effective in excluding dirt and bacteria and which 
is at the same time practical has resulted in the development 
of a number of styles of covered milk pails. The purpose 
sought in all of these is the same; namely, to reduce as far 
as possible the area through which dirt and dust can fall 
into the pail. The amount to which the opening can be re- 
duced is necessarily limited because a certain sized opening 
is necessary for the practical operation of any pail. In the 
following pages of this article the writer desires to report 
the results of some tests made with some of the styles of 
covered milk pails which have come under his notice. This 
is not intended to be a complete test of the various forms of 
pails now in use for there are other styles which are not in- 
cluded in this report but these results are given with the hope 
that they may prove suggestive and useful to some dairymen. 
In Bulletin 25 of this Station the writer reported certain tests 
made with the Stadtmueller covered pail. Since the publica- 
tion of that report considerable more work has been done with 
this pail and the results are here given in part. 
GENERAL METHOD OF THESE EXPERIMENTS. 
In all of the experiments reported in this paper certain gen- 
eral methods were followed uniformly while the details varied 
somewhat according to the nature of the different tests. In 
all of the work the milk pails and other materials coming in 
contact with the milk were thoroughly sterilized in steam 
previous to use. In most cases the udder and flank of the 
cows were wiped with a damp cloth just before milking in 
order to remove any loose dust and dirt which might adhere 
to the cow. For this purpose the cloth was moistened in clean 
water without the use of any germicide. As soon as the 
samples were obtained they were taken to the laboratory 
where tests were immediately made. The number of bacteria 
