Eggs are tested by holding them toward the light. If tiny spots present themselves it is not newly laid. If a large spot appears, the egg is bad, and should never be used. The yolk of an egg is the most nutritious part; the white of an old egg is compact and difficult to digest. Hen's eggs are considered the best; turkey eggs not quite so mild; goose eggs large and well flavored; duck eggs are, perhaps, richer and stronger in taste than any other.