The following tests may be used to determine whether eggs are fresh: (1) The shell of a fresh egg is rough, not smooth and shiny; (2) a reasonably fresh egg will sink in salt water made by dissolving 1/3 cup of salt in 1 quart of water while a stale egg will float; (3) when an egg is candled, that is, held against an opening in a shield around a bright light, a fresh egg will appear clear inside and the air cell will not be larger than a nickel; (4) a fresh egg makes no sound when it is shaken.