Odors in Milk. 15 



any of these principles still remain in the blood at the 

 time the milk is being drawn they will appear in it. It 

 follows, therefore, that the longer the interval of time be- 

 tween the taking of food into the body and the drawing 

 of the milk the less danger there will be of the milk be- 

 ing tainted by it. The reason for this is found in the fact 

 that the milk is excreted during the time of milking while 

 the blood is coursing through the udder, carrying whatever 

 odor producing substances may then be present. 



13. Time to Feed Odor Producing Foods. It is clear from 

 what has been said that if it is desired not to have the 

 milk charged with the undigestible odor-principles of food 

 while it is being drawn these foods shun Id be fed as soon 

 as possible after milking and never just before in order 

 that time enough may have elapsed to permit the odor 

 principles to have been eliminated from the blood by the 

 other organs. On the other hand, if the food contains a 

 principle whose odor is desired in the milk, then the re- 

 verse rule as regards time of feeding should be practiced, 

 namely, to feed these just before milking. 



14. Introduction of Odors Into Milk From the Air. It is 

 the fact that the molecules of substances are not in contact 

 and that they are in motion which makes it possible for 

 milk when in an atmosphere containing odors to become 

 charged with them. If the odors of manure, of urine, 

 of ammonia, or any of those associated with the decay 

 of organic matter are in the air above the milk the rapid 

 motion of these molecules will ca*use some of them to 

 plunge into the milk and accumulate there until they be- 

 come so numerous that just as many tend to escape per 

 minute as tend to enter. The milk is then saturated with 

 the odor in question. 



The warmer the air surrounding the milk and the 

 warmer the milk the more quickly will the condition oi 



