186 



AUSTRALIAN AGRICULTURE. 



Pasteurising Pail. 



Preserving Milk by Heating. The object of 

 " Pasteurising " milk is to destroy " the bacterial germs " 

 of fermentation or decay. But by " scalding " up to 

 the boiling p.p.jnt, milk is injured seriously. As it 

 becomes known that the germs can 

 be destroyed much more effectively 

 while the milk is at a temperature 

 far below the boiling point, the 

 f-afer and better process is followed. 

 Germs in milk, both vegetable and 

 animal are destroyed, and the milk 

 effectively " Pasteurised " at a tem- 

 perature of 155 degrees. The 

 apparatus shown in our illustrations 

 is quite effective for the purpose. 

 The can or pail (A) is fitted up as 

 seen in the second illustration. The 

 bottles (B) (B) (B), as many as may 

 be required, or the pail can hold, 

 are filled with milk, or other fluid 

 substance to be sterilised. The 

 bottles stand upon a perforated 

 grating (D), and are surrounded 

 by water as shown. luto each 

 bottle is inserted a plug (c)(c)(c) 

 of cotton wool or other porous 

 substance. Heat is then applied 

 gradually to the vessel, and 

 brought to about 155 degrees. 

 Thirty minutes of that tempera- 

 ture is ample, as a rule, for sterilis- 

 ing the contents of the bottles, and 

 milk thus treated will remain sweet 

 during several days. The object E- 

 of the porous stoppers is to allow 

 the escape of vapours from the contents of the bottles, 

 while preventing the admission of any other vapours. To 

 finish the process up to the point of actual sterilising, 

 the water is brought up to nearly the boiling point, or 

 200 degrees, for three minutes or so, and the bottles 



