There is no infallible mode of ascertaining the freshness of an egg before you break it, but unless an egg is perfectly good, it is unfit for any purpose whatever, and will spoil whatever it is mixed with. You may judge with tolerable accuracy of the state of an egg by holding it against the sun or the candle, and if the yolk, as you see it through the shell, appears round, and the white thin and clear, it is most probably a good one; but if the yolk looks broken, and the white thick and cloudy, the egg is certainly bad. You may try the freshness of eggs by putting them into a pan of cold water. Those that sink the soonest are the freshest; those that are stale or addled will float on the surface.
There are various ways of preserving eggs. To keep them merely for plain boiling, you may parboil them for one minute, and then bury them in powdered charcoal with their small ends downward. They will keep a few days in a jar of salt; but do not afterwards use the salt in which they have been immersed.
They are frequently preserved for two or three months by greasing them all over, when quite fresh, with melted mutton suet, and then wedging them close together (the small end downwards) in a box of bran, layer above layer; the box must be closely covered. Charcoal is better than bran.
Another way (and a very good one) is to put some lime in a large vessel,and slack it with boiling water, till it is of the consistence of thin cream; you may allow a gallon of water to a pound of lime. When it is cold, pour it off into a large stone jar, put in the eggs, and cover the jar closely. See that the eggs are always well covered with the lime-water, and lest they should break, avoid moving the jar. If you have hens of your own, keep a jar of lime-water always ready, and put in the eggs as they are brought in from the nests. Jars that hold about six quarts are the most convenient. It will be well to renew the lime-water occasionally.