130 MODERN DAIRY PRACTICE. 



water proper is always free from bacteria. Frankel's in- 

 vestigations show that this is the case even where the 

 water is derived from strata of the earth under highly 

 polluted places. Artesian well-water is therefore as a rule 

 sterile. 



The water in a creamery well ought of course prefer- 

 ably to come from deep-soil layers. By digging a deep 

 well another advantage is secured from the fact that the 

 deeper the layer from which the water comes the colder it 

 naturally is, and, as is well known, a low temperature will 

 check the bacteria to a large extent. In comparing the 

 rapidity in the development of the same kind of bacteria 

 from the upper strata of soil and from lower strata 

 Reimers found that the latter showed a considerably slower 

 development ( Wachsthumsverlangsamting) than the former 

 a relation which appeared the sharper the deeper the 

 well. 



In case of doubt whether the water available in a 

 creamery is fit for use, it will not do to make only a chem- 

 ical examination, but it must also be analyzed bacteriolog- 

 ically. The difficulty with the latter examination is, that 

 the sample must be analyzed as soon as taken. It cannot 

 therefore be sent away for bacteriological examination, but 

 the bacteriologist himself must take the sample and begin 

 the analysis at once. If the bacteria in the sample get 

 time to increase before the examination is made, it will 

 not be possible to find the original bacterial content of the 

 same. Owing to the fight between the different kinds of 

 bacteria mentioned in the preceding chapter, the true rela- 

 tion between the different forms can then, furthermore, 

 not be ascertained a point which is of course important 

 in judging the applicability of the water. Heraeus fixes 



