70 A Xczu Dairy Industry. 



with isolating material ; at k we see the automatic 

 regulator, an exceedingly sensitive and ingenious ar- 

 rangement, registering changes in the temperature of 

 one-fifth of one degree ; t, is the thermometer ; b, d 

 and 1, is an arrangement for supplying moist air to 

 the heating chest ; o, is the ventilating chimney ; c, 

 m and s, the heating apparatus, coal oil or benzine 

 being used in the lamp. Now, from each days pro- 

 duction of sterilized milk we retain two sample bottles, 

 and pasting a label on the side of each bottle, record on 

 it the date of sterilizing and grade of milk contained in 

 the bottle. The bottles are now placed in the heating 

 chest of the thermostat and the regulator set to main- 

 tain 05°, F., which is the temperature most propitous 

 to the propagation and multiplication of bacteria. 

 Morning and evening these bottles must be taken 

 out, their contents, shaken and attentively investi- 

 gated as to an}- change in their condition. If any 

 bacteria or their spores have escaped the effects of 

 sterilization then they will speedily be brought to 

 development and their action on the milk noticeable. 

 The time, therefore, which milk will keep in un- 

 changed condition in this incubator is a fair indication 

 of how long such milk will keep in good condition 

 when kept at lower temperatures. Milk that will 

 keep perfect in this brooder for twenty-four hours is 

 likely to keep perfect for one week at 00°, or below, 

 and milk that keeps for eight days in the chest with- 

 out curdling will, undoubtedly, keep good for eight 

 \.:cks if kept in an ordinary cellar, and ever so much 



