REDUCTION OF BACTERIAL CONTAMINATION, 5! 



and it is therefore necessary to emphasize the precaution of 

 keeping all milk vessels away from any possible contact with 

 contagious diseases. The vessels should not be allowed to 

 stand open near barnyards or piggeries, under trees, nor 

 beside roadways where dust can blow into them. 



The Water Supply. The water supply of the dairy is one 

 of the most important factors in relation to the healthfulness 

 of milk. Instances are now quite numerous of typhoid fever 

 being distributed through the milk, the source of which is 

 sometimes traced directly to the water supply. So distinctly 

 is this true that some large dairy companies refuse to accept 

 milk from a farm unless they have had an opportunity of 

 making a chemical and bacteriological analysis of the water 

 used in the dairy. This does not apply to the water which the 

 cows drink, but to the water which is used in the dairy for 

 washing the milk vessels. The water drunken by the cows 

 rarely, if ever, has an opportunity of contaminating the milk, 

 for, as we have seen, bacteria do not pass through the milk 

 glands; but the water used in washing the milk cans, 

 particularly if they are rinsed with cold water, may find its 

 way into the milk and produce trouble. Every dairyman 

 should, therefore, be particular as to the water supply used 

 in the dairy, and it should be always remembered that no 

 well which is located near a house, or near any privy vault, 

 is safe from contamination with disease bacteria. The 

 farmer's well, if near his house, is quite unsafe for washing 

 the milk vessels. 



Milking. If milk could pass directly from the milk duct. 

 to a sterilized milk vessel the number of bacteria it would 

 contain would be small. These would frequently include 

 no acid bacteria and those that were present would usually 

 be of comparatively little importance. Such a method of 

 milking, however, is practically impossible. Several at- 

 tempts have been made to devise milking machines which 

 shall carry the milk directly from the milk glands to the 



