PEEPARATION OF MEDIA. 81 



XXX. Nitrate Solution. 



0.5 gm. NaCI. 

 1.0 gm. peptone. 

 0.2 gm. KNOj. 

 1,000 cc. water. 



2. Pill into test tubes and sterilize as iisital. 



XXXI. Milh. 



1. The milk should be obtained from a clean dairy and if 

 not free from cream should be filtered or separated. 



2. 10 ec. portions in test tubes are sterilized in the steam 

 sterilizer for 15 minutes on each of four consecutive days. 



3. After standing a week the milk is ready for use. 



XXXII. Litmus Milh. 



1. Fresh separated milk is employed. 



2. To each 100 cc. add 2 cc. of a saturated solution (1 

 gm.-16 cc. water) of blue litmus. 



3. 10 cc. portions in test tubes are sterilized in the steam 

 sterilizer for 15 minutes on four consecutive days. 



