Machiiie- versus Hand- Drawn Milk. 423 



suit of overalls and cap for each milking, and received instruc- 

 tions from the supervisor throughout the season on sanitary- 

 methods in the production and handling of milk for infants, 

 the same staff being employed right throughout the season." 



Possible Sources of Bacterial Contamination. 



Before describing in detail the results of the investigation 

 it may be well to consider this subject. 



It is well known that from many cows, provided that strin- 

 gent precautions are taken, small quantities of absolutely 

 sterile milk can be secured. Such extravagant precautions are, 

 however, impossible in ordinary hand-milking conducted as a 

 commercial undertaking. All that can be done is to minimise 

 as far as possible the known sources of contamination. That 

 much may be achieved in this direction is proved by the results 

 not only of the examination of milk from the special cows 

 reserved for this comparative test, but also by the results 

 obtained by Dr. Bull in his examination of the general milk 

 supply of the Lady Talbot Milk Institute. (See Report for 

 1911, p. 15.) 



In hand-drawn milk the chief sources of contamination 

 are : — 



1. The milker's hands, and to some extent, his garments. 



In many cases there is no doubt that such are very 

 important factors, especially where the method known 

 as wet-milking is pursued. 



2. The skin of the cow, particularly that covering the 



udder and teats. This is a common source of infec- 

 tion, for often no precautions are taken in regard to 

 thorough washing of the udder and grooming of the 

 flank, consequently scurf, etc., frequently enter the 

 pail. 



3. Atmospheric dust and manure particles falling into the 



bucket during and subsequent to the process of milk- 

 ing. 



4. The milk in the teat duct. It is well known that the 



first milk invariably shows a much larger bacterial 

 content than the average milk, due to invasion by 



