It is because when it is placed in a freezer, the cold slows down the chemical reaction that makes it glow. Basically, you freeze the chemicals inside the glow stick.
Montag and his coworkers are firemen who burn books in a society where books are forbidden. So, when they do this, when they throw all of these books into the fire, their faces are lit and sunburnt by these real fires they made, as well as the ones found in the books themselves.
It should be like this: The plant can holds 3.5 liters in its largest pitchers. 3.5 liters is more than half-a-gallon.
