54 FACTORY SANITATION 



heads." Patrons sending such milk should be looked after at 

 once. 



If the curd dissolves, or no curd is formed and the milk 

 changes into a transparent liquid, it usually is contaminated by 

 germs from the dust of hay and bedding, or polluted water. To 

 this class of organisms belong Bacillus subtilis, Bacillus fluores- 

 cens liquifaciens, Plectridium foetidum. Bacillus putrificus, etc. 

 Some of these are violent gas producers and most of them are 

 spore-bearers. They are the cause of ihe most disastrous milk 

 defects. Dairies from which such milk comes should be vigor- 

 ously inspected and all milk from them should be rejected, until 

 the patrons have learned how to furnish sanitary milk. 



Milk that remains unchanged for twenty-four hours when 

 subjected to the fermentation test, suggests that it contains some 

 preservative. It is possible, however, for milk produced under 

 ideally sanitary conditions to remain normal and unchanged even 

 at these high temperatures for several days. Where milk comes 

 to the factory in bulk as is the case in the condensery, samples 

 showing abnormal keeping quality should be regarded with sus- 

 picion, and the respective dairies should receive immediate and 

 thorough inspection. 



Tests for Butterfat and Specific Gravity. In the factories 

 where the milk is. not paid for on the butterfat basis, composite 

 samples should be taken daily, to be tested for fat and specific 

 gravity, at regular intervals of from two to four weeks, in order 

 to detect possible adulterations by skimming or by the addition 

 of water. For specific directions for the Babcock test, the use of 

 the lactometer and tests for preservatives see Chapter XXX 

 " Chemical Tests and Analyses of Milk and Milk Products." 



FACTORY SANITATION. 



In the previous paragraphs, special emphasis was placed on 

 the great importance of a good quality of fresh milk. It is equally 

 essential that the factory be kept in exemplary condition as to 

 cleanliness and sanitation. This is necessary because of its effect 

 on the 'patrons and on the wholesomeness and marketable prop- 

 erty of the finished product. 



Effect on Patrons. It does not take the watchful eye of the 

 intelligent patron, who daily comes to the factory, very long to 



