THE PREPARATION OF CERTAIN SPECIAL MEDIA 35 



100 c.c. of agar (17). Take 50 c.c. of it for glycerin agar, 

 and to the remainder add 1% glucose. Dissolve the pow- 

 dered glucose in about 5 c.c. of boiled, hot water before add- 

 ing it to the liquid agar. After thoroughly mixing distribute it 

 in small, sterile test tubes. Sterilize, wipe, label, and store the 

 same as ordinary agar. 



55. Preparation of Glycerin Agar. — Take 50 c.c. of the 

 agar prepared above, and add S% °f P^^e (c. p.) glycerin. 

 Thoroughly mix it with the agar, after which distribute it in 

 tubes. Sterilize, label, and store as ordinary agar. 



56. Preparation of Glucose Bouillon. — This is used in the 

 fermentation tube. Take joo c.c. of sugar-free peptonized 

 bouillon (59), and add i gram of pure grape sugar (glucose). 

 After it is dissolved and thoroughly disseminated through the 

 bouillon by stirring or pouring, distribute the bouillon in 3 fer- 

 mentation tubes, iiUing completely the closed branch and the 

 open bulb about half full, and put 7 c.c. in each of 5 small 

 sterile test tubes. Sterilize by discontinuous steaming for 20 

 minutes each day for 3 consecutive days. The tubes should 

 be wiped, labelled, and placed in the locker until needed for 

 use. 



57. Preparation of Lactose Bouillon. — This is prepared by 

 adding 1% of pure lactose (milk sugar) to the peptonized 

 sugar-free bouillon. It is necessary that the bouillon, used does 

 not contain muscle sugar. After adding the lactose, which has 

 been dissolved in a few c.c. of the bouillon and thoroughly 

 mixing it in the bouillon, distribute in fermentation tubes and 

 small test tubes, sterilize, label, and store the same as the glu- 

 cose bouillon. 



58. Saccharose Bouillon. — This is peptonized sugar-free 

 bouillon to which 1 9?? pure saccharose (cane sugar) has been 

 added. It is prepared from bouillon free from muscle sugar 

 in the same manner as lactose bouillon. 



59. The Preparation of Sugar-free Bouillon. — Bouillon pre- 

 pared by the ordinary method usually contains small quantities 



