28 Director's Report of the 



cleanliness of the walls, the cleanliness of the animals and their 

 attendants, the condition of the barn air, or in fact any other 

 factor. 



For the last five or six years, the Station has been engaged in 

 a study of the relative influence and importance of these factors. 

 These studies have been instituted on the theory that in the pro- 

 duction of thoroughly sanitary milk, too much importance is being 

 given to certain operations and that milk of the most healthful 

 character may be placed on the market without the excessive cost 

 that has been incurred by certain certified milk producers. These 

 investigations are still in progress. 



Certain results have been made public, however. Probably no 

 single factor has a greater influence upon the bacterial content of 

 the milk than the form of milk pail used, and attention was first 

 given to this part of the problem. The inquiry involved a com- 

 parison between the old type of open pail and pails with a partially 

 closed top. These tests were extensive and were made under such 

 conditions as could be steadily maintained in good dairy manage- 

 ment and tests were made only when these conditions seemed to be 

 normal. Various narrow-mouthed pails were compared with the 

 open pail. A large number of observations showed that the covered 

 pail reduced the number of bacteria in the milk from 50 to 70 per 

 ct. The covered pail is now in general use in stables where an at- 

 tempt is made to improve the sanitary quality of the milk. 



One of the most important publications issued by this Station 

 is Bulletin ISTo. 337, giving the results of an effort at improving 

 the milk supply of the city of Geneva. The connection of the 

 Station with this municipal experiment was indirect and unoffi- 

 cial. In 1907, the head of the Bacteriological Department of the 

 Station became a member of the Geneva board of health and in 

 this way an opportunity was offered for an officer of the Station 

 to aid in instituting an effort at improving the milk supply of the 

 city, which, at that time, was none too good. 



The means adopted for securing an improvement in the sani- 

 tary condition surrounding the production of the city milk supply 



