64 
HOUSEHOLD BACTERIOLOGY 
■Experiments 
with 
Bacteria 
Experiment III. Take seven clear glass bottles, 
number or mark each in some way. (Small laboratory 
flasks with flat bottoms are convenient for this pur¬ 
pose.) Put into each one-half cup or less of milk or 
grape juice. 
Leave No. i open in a warm room, not in direct 
sunshine. 
Fit No. 2 with a full plug of cotton wool about one 
inch long. Put with No. i. 
Have No. 3 like No. i, but place immediately in an 
ice box. 
Drop into No. 4 one tablet or “saloid” of corrosive 
sublimate. This can be bought of a druggist. Mark 
it “Poison.” Plug like No. 2 and place it with No. 1. 
Plug No. 5 with cotton wool like No. 2. Put it into 
a steamer and steam for thirty minutes three days in 
succession. Place it with No. 1. 
Fit No. 6 with a tight cork. Remove the cork, but 
place it with the bottle in the steamer and steam as 
you did No. 5. Cork each bottle while the steam is 
coming out. As the cork cools and shrinks, tighten it. 
Put a cotton wool plug into No. 7 and heat for half 
an hour from 155 0 F to 165° F. 
After completed preparation, keep all but No. 3 
under the same conditions and note any changes that 
occur. Test the open bottles with strips of blue litmus 
paper from the druggist’s. See if the contents change 
the paper any more rapidly or completely after two or 
three days than at first, Test by smell and taste all 
