GENERAL BACTERIOLOGY 
115 
“anaerobic jar” and incubating it in the usual man¬ 
ner. 
If such a jar is not on hand, a 2 per cent glucose meat 
infusion agar (not slanted) is inoculated by stabbing 
and about 3 to 5 c.c. of liquid paraffin is poured on the 
top of the agar. 
Another very simple method is as follows: a tube of 
slanted agar is inoculated in the usual manner, the stop- 
Fig. 21A.—The incubator. 
per is removed, and the tube is inverted into a beaker 
containing a gram of dry pyrogallic acid. About 10 c.c. 
of a 5 per cent solution of sodium hydroxide are then 
poured into the beaker and this is then covered with a 
half-inch thick layer of liquid paraffin. 
4. Making Plates. —If a smear examination or the 
appearance of the culture suggests that more than one or¬ 
ganism is present and it is desirable to isolate them in pure 
culture, one must “prepare plates”: three tubes of agar 
are melted and cooled to 42° C. A platinum loopful of 
