}48 Effect of External Influences. 



cleaned. In the milk room the milk is further treated by another 

 straining and cooled by simultaneous aeration after which it is 

 either directly filled into bottles, cans or collected in a vat in order 

 that it may be thoroughly mixed. 



The milk should be handled as little as possible, since each 

 manipulation not absolutely necessary, means a poorer condition 

 of the product from a hygienic standpoint. The producer there- 

 fore after straining the milk through cotton strainers should cool 

 it and fill it into clean bottles or well-galvanized and properly 

 cleaned cans. 



The straining of milk through straining cloths which have 

 been carelessly cleansed by rinsing in cold water, and which in 

 most instances fail to answer the purpose on account of their large 

 meshes, is, it is to be regretted, in most instances merely a pre- 

 tense, which only tends to further spoil the dirty milk. Milk which 

 is obtained in an unclean way cannot be deprived of its poor 

 qualities by any mechanical means, since the filth dissolves and the 

 bacteria pass through the straining cloths and the cotton filter. If 

 the accidentally contaminating bacteria are removed immediately 

 during the milking (cotton filter in the funnel of milk pail), a con- 

 siderable improvement of the milk results. The value of artificial 

 cleaning, however, will continue to decrease in proportion to the 

 length of time elapsing between the time of milking and cleaning. 

 If the cleaning of dirty milk is accomplished only hours afterwards 

 at the collecting places and creameries it should be considered as 

 direct fraud, which gives the product the appearance of good qual- 

 ity without however improving it in any way. In such cases filtra- 

 tion and centrifugalization only serve as means of deception. 

 Filthy milk which has been subsequently cleaned, must in spite of 

 its cleaned condition be considered as spoiled in the sense of the 

 pure food law, even if no changes are yet apparent in it. 



In milk control work there are frequent opportunities for 

 confiscating dirty market milk, and not infrequently the examina- 

 tion reveals that the contamination of the milk consists in dust- 

 sized particles and cow manure, all of the same caliber, which in- 

 dicates that the milk has been subjected after milking, to a straining 

 process which permitted the manure particles which had been dis- 

 integrated during the process of milking to pass through the 

 strainer. Unstrained milk obtained under filthy conditions usual- 

 ly shows the presence of course straw particles, manure, bits of fod- 

 der and cow hair. 



After straining, the milk is allowed to flow down over the out- 

 side of a double corrugated surface, or a series of parallel horizon- 

 tal pipes for the purpose of cooling and simultaneous aeration; 

 these surfaces are kept cool through pipes containing running 

 water, ice water or brine. Especially practicable and serviceable 

 are the so-called round coolers which are provided with spiral 

 pipes, covered with tinned-copper sheets, over which the milk runs 

 in a thin layer. 



