Contamination of Milk. 35 



the city of Berlin, Germany, contains about three hundred 

 pounds of dirt and filth. 



From a large number of determinations of the solid im- 

 purities found in market milk, Renk ! deduces the follow- 

 ing rule: If a sample of milk shows any evidence of im- 

 purity settling on a transparent bottom within two hours, 

 it is to be regarded as containing too much solid impuri- 

 ties. These solid particles, composed largely of manure 

 and dirt, are always teeming with bacteria, especially with 

 putrefactive and decomposition organisms. 



While the number of bacteria that are hereby introduced 

 into milk is at times large, the character of the species is 

 even more significant. Derived primarily, as most of them 

 are, from fecal matter or from dirt, it is little wonder that, 

 their introduction should call forth abnormal fermenta- 

 tions. Undoubtedly bacteria of this class are intimately 

 concerned in the production of intestinal troubles in in- 

 fants. Eckles 2 has shown that the digesting bacteria 

 that accompany fecal matter are closely connected with the 

 peculiar winter flavors that impair the quality of winter 

 butter. 



Influence of the milker. The condition of the person 

 of the milker is not to be ignored in determining all pos- 

 sible factors of infection, for when clothed in dust-laden 

 garments, dislodgment of bacteria takes place readily. 

 Particular attention should be paid to the hands of the 

 milker. The filthy practice of moistening the hands with 

 a few drops of milk is to be deprecated from every point 

 of view. The milker should wash his hands in clean 

 water just before milking. If something is needed to en- 



Renk, Cent. f. Bakt., 1891, 10:19$. 



2 Eckles, Bull. 59, Iowa Expt. Stat., Aug. 1901. 



