FACTORY SANITATION 49 



largely from manure and other filth. Among these are Bacillus coli 

 communis, the natural inhabitant of the colon of the animal, and 

 butyric acid organisms which are spore bearers. The latter espe- 

 cially may give rise to serious milk defects, causing "swell 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 fluorescens 

 liquifaciens, Plectridium foetidum, Bacillus putrificus, etc. Some 

 of these are violent gas producers and most of them are spore-bear- 

 ers. They are the cause of some of the most disastrous milk defects. 

 Dairies from which such milk comes should be vigorously 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 sub- 

 jected to the fermentation test, suggests that it contains some pre- 

 servative. 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 fac- 

 tory in bulk as is the case in the condensery, samples showing ab- 

 normal keeping quality should be regarded with suspicion, 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 butter fat 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 XXXI "Chem- 

 ical Tests and Analyses of Milk and Milk Products" and Chapter 

 XXXIII "Detection of Adulterants and Preservatives, Etc," 



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 clean- 

 liness and sanitation. This is necessary because of its effect on the 



