GENERAL BACTERIOLOGY 
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(b) Strain through gauze, heat slowly to boil, add 
15 to 17 grams of shredded agar; when dissolved, neu¬ 
tralize to 0.4 per cent acid (phenolphthalein). 
(c) Cool to 60° C. add three whole eggs (beaten with 
a little water), put back on fire, heat quickly to boil, 
then turn the flame down to a simmer for fifteen min¬ 
utes. 
(d) Filter through cotton and gauze (both previously 
sterilized), add 10 grams of Squibb’s cornstarch per 1,000 
c.c. of medium, rub the starch with 60 c.c. of filtrate to 
a milky consistency, pour back into the rest of filtrate 
and shake well. (If lumps are present filter again and 
add more starch.) 
(e) Sterilize in Arnold’s sterilizer, shaking every ten 
minutes. 
(f) Tube or flask. Autoclave fifteen minutes at 8 to 
10 pounds pressure. 
(g) Cool down to 42° C., tilt a few times (without 
wetting the stopper), slant overnight, then stand them 
up for a day. Good tubes show about % of an inch of 
water of condensation. 
16. Bile Medium. Used in Blood Cultures 
Take 900 c.c. of fresh ox bile, 100 c.c. of glycerin and 
20 grams of peptone. Put in small Erlenmeyer flasks 
(about 40 to 50 c.c. in each) and sterilize in Arnold’s 
sterilizer for thirty minutes for three successive days. 
17. Medly for Tubercle Bacillus 
The best media are those of Petroff; their preparation 
requires a good deal of skill, and the reader should con¬ 
sult Petroff’s own description observing the most min¬ 
ute details. 
