grees, F. But physiologists claim that wlieu milk is heatetl 

 167 degrees, F., it uudergoes a chemical change that impairs 

 its digestibility and nutritive value. By heating milk higher 

 than 167 degrees, F., its starch dissolving ferment is destroy- 

 ed ; a part of the albumin is coagulated, and the caseine will 

 not readily coagulate in the presence of rennet. By pro- 

 longed heating of milk at a high temperature, the fat glob- 

 ules separate from the milk and this is said to interfere with 

 the assimilation of the fat. Prolonged heating at a high 

 temperature is said to destroy the milk sugar. But accor- 

 ding to the bacteriologists and physiologists, heating milk 

 to 14:0 167 degrees, F., Avill kill the adult forms of all 

 kinds of germs, preserve the milk and render it more health- 

 ful, without impairing its value, in any way as a food. 

 These comparatively low temperatures will not destroy the 

 spores of many decomposition ( septic ) germs ; consequently 

 the milk "sours" in the course of 24 hours, or as soon as 

 the spores develop into adult microbes. According to Fraen- 

 kel, heating cholera bacilli to 122 degrees, typhoid bacilli to 

 140 degrees, or tubercle bacilli to 158 degrees, F., will de- 

 stroy them in a short time ; this is especially true if the 

 bacilli are in such liquids as milk or water when heated. 

 Furthermore, it is a;lmost absolutely certain that none of 

 these three germs form spore«i. 



If one should desire to keep the milk indefinitel}^, it must 

 be heated as above directed for three consecutive days. To 

 raise the temperature of the milk to 185 degrees, varying 

 from that up to 205 degrees, F., fill the vessel, C, with cold 

 water, one-third to one-half as high as the level of the milk 

 in the bottles ; then boil the water in the vessel 20 to 40 

 minutes, usually 80 minutes is sufficient to preserve the milk 

 2 to 4 days, Repeat the process the next day and the milk 

 may be preserved indefinitely. I prefer this method to the 

 preceeding for sterilizing milk in the summer. 



To raise the milk or water in the bottles to 206 or 212 de- 

 grees, F., fill the sterilizing vessel with cold water as high as 

 the level of the milk or water in the bottles, cover the vessel 

 with a non-perforated lid, or cover the j^erforated lid with 



