12 THE MODERN MILK PROBLEM 



in sanitary science is to distinguish between the vari- 

 eties that are, or may be, accompanied by infection, 

 and those that ordinarily are not. Nevertheless dirt 

 of any kind is in itself undesirable. 



The instinct of decency is not without meaning. It 

 is a protective instinct, and it is supported by the 

 general fact that dirt is suspicious. There are places 

 where dirt is naturally to be found, but when it is 

 " matter out of place" it is a sign that something is 

 wrong. We are not surprised to see muck in the 

 gutter; we do not shudder at manure hi a manure bin; 

 but when we perceive foreign matter in a milk bottle 

 we are rightly disquieted. The soiled hands of the day- 

 laborer are the result of honest toil; the unwashed but 

 milk-wet hands of the dairy worker excite revulsion. 



This instinct has applications which are without 

 sanitary significance. But in the matter of food it is 

 truly protective. We have spoken above of "dirt" in 

 a general sense. But ordinary dirt shades into filth, 

 such as the manure of the cow stable: from contamina- 

 tion it is but a step to pollution, and pollution may mean 

 infection. 



It is possible to make theoretical distinctions be- 

 tween various forms of contamination, and it is possible 

 to devise practical measures which lay stress upon the 

 more dangerous. But both decency and experience 

 aver that we should avoid all forms of contamination. 

 Decency is, in short, a rough (though, as we shall see 

 later, an incomplete) insurance of safety. But even 

 though we are able to secure complete safety by other 

 means, we should still desire the greatest degree of 

 decency that we can obtain. Decency, as North points 



