THE PREPARATION OF CERTAIN SPECIAL MEDIA 41 
blue color to the milk. Sterilize, wipe, label, and store the 
same as the milk. The litmus solution will be furnished. 
57. Preparation of glucose (grape sugar) agar. Take 30 cc. 
of agar previously prepared (§ 18), liquefy, and add 1% glu- 
cose while hot. After thoroughly mixing, distribute it in small 
sterile test tubes. Sterilize, wipe, label, and store-the same 
as ordinary agar. ( ' 
58. Preparation of glycerin agar. Take 50 cc. of the agar 
previously prepared and add 5% of pure (c.p.) glycerin. 
Thoroughly mix it with the agar, after which distribute it in 
tubes. Sterilize, label, and store as ordinary agar. 
59. Preparation of glucose bouillon. This is used in the 
fermentation tube. Take 100 cc. of sugar-free peptonized 
bouillon (§ 62) and add 1 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 
fermentation tubes, filling completely the closed branch and 
the open bulb about half full, and put 5 cc. 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, labeled, and placed in the locker until needed for use. 
60. 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 
Joes not contain muscle sugar. After adding the lactose, 
which has been dissolved and thoroughly mixed in a few cubic 
séntimeters of the bouillon, distribute in fermentation tubes 
ind small test tubes, sterilize, label, and store the same as 
the glucose bouillon. 
61. Saccharose bouillon. . This is peptonized sugar-free bou- 
lon to which 1 % pure saccharose (cae sugar) has been added. 
[t is prepared from bouillon free from muscle sugar in the 
ame manner as lactose bouillon. 
62. Preparation of sugar-free bouillon. Bouillon prepared 
xy the ordinary method usually contains small quantities of 
