Canned fish or other meats spoil very quickly after the cans are opened, and should be eaten the same day.
~7.

Adulterated Foods.~--Many of our foods are sometimes spoiled or injured by persons who put into them cheap substances which are harmful to health.

They do this so as to make more money in selling them.

This is called _adulteration_.

The foods which are most likely to be injured by adulteration are milk, sugar, and butter.
~8.~ Milk is most often adulterated by adding water, though sometimes other things are added.