Agricultural Gazette of N.S.W., July 2, 1920. 



Agar Plate of air exposure for 2^ minutes in tlie cold room 

 at chilling temperature. 



Note the slistht infection by nioukls, &c. 



(Original.) 



C7 



Agar Plate of air exposure for 2j minutes in the churn room. 

 .Note tlie purity of tlic air, tlie locality being an elevated one. 



(Orif^iiial.) 



