IXDUSTKTICS DKPKNDIXC. ON ANIJIAL PROHUCTS I363 



2) Hand milking on the methods generally practised ; 



3) Mechanical milking, steam being used for^cleaning^the appliances 

 under special laboratory conditions. 



4) Mechanical milking, using hot solutions of caustic soda for clean- 

 ing the appliances under normal conditions in the cow-shed and without the 

 use of steam ; 



5) Hand milking with special methods of cleaning. 



The results of the bacteriological analysis comprising the determina- 

 tion of the number of bacteria per cc. , the presence of gas-producing bacte- 

 ria of the group of Bacterium coli, and their behaviour under the fermenta- 

 tion test, led the writers to the following observations : 



i) The quality of the milk as regard the species and number of the 

 bacteria it contains, varies within much wider limits in mechanically milked 

 ' than in the hand milked article, as an incomplete cleaning of the apparatus 

 facilitates the accumulation of a large number of bacteria which, at the 

 following milking, easily get into contact with the milk which is almost free 

 from germs on leaving the teat. This deteriorates the keeping properties of 

 the milk, and the latter must be regarded as of inferior quality both from the 

 point of view of health and that of the dairy industry. 



2) On the other hand, by using special methods to ensure the utmost 

 cleanliness of mechanical milking appliances, there is obtained on this me- 

 thod a quahty of milk which, with respect to purity and keeping properties 

 and the number of bacteria it contains, answers all requirements ; it is 

 superior to any hand milked product, on condition, of course, that the ap- 

 pliance is applied to a perfectly clean teat. 

 ^ . 3) In order to obtain an equally high degree of purity with mechan- 



y ical milking, it suffices to use a hot solution of 0.2 % strength of soda (47 

 to 50° C) when cleaning the appliances inside and out which the brush, flush- 

 ing them out before and after with a jet of clean water. 



4) In view of the facility with which mechanical milking may cause 

 deterioration in the quality of milk when the above rules are not constantly 

 and strictly, followed, it is desirable, both in the interests of hygiene and 

 the dairy industry, that wherever the introduction of this method of milk- 

 ing is justified from the economic standpoint, it should only be entrusted to 

 conscientious and trustworthy persons. 



1023 - A New Defect in Milk Caused by Bacterium Lactis Aerogenes Esche- 



rich. — DuGGELi Max, in Zcitschrift jiir Guruniisphysioloi^ie, Vol. 5, No. 3, pp. 321-340. 

 lydpzig, 1 91 6. 



The writer received for examination 2 samples of bottled milk suffering 

 from a hitherto unknown and very pronounced defect, although the sam- 

 ples reached the laboratory only 48 and 60 hours after milking. They came 

 from a model cow-house of 36 cows ])roducing best quality milk, ob- 

 tained and handled with the utmost cleanliness, afterwards filtered, cooled 

 to I2-I4"C and bottled for forwarding to the consumers. When the milk 

 from this shed had been kept for some time, a bitter taste was observable, 

 together with a typical rancid smell, especially noticeable when boiling the 



