after boiling is clean.

Q — I see that you find nothing in this method that violates the rules of health for preserving the benefits of milk!

A — This boiling process does not affect the properties of the milk. But it does give it a particular odor, affects its constituents to a certain extent, converts part of its soluble salts — calcium phosphate above all — into an insoluble substance, and damages some of the vitamins it contains, especially vitamin C. All these changes reduce its usefulness. I advise mothers not to feed their children constantly on boiled milk, since it has lost some of its essential elements.

Q — And do you consider this the only method, in its simplicity and its practicability, that can be followed in the kitchen?

A — The best of the simple methods followed in boiling milk is to fill it into small bottles which are closed and placed in a vessel, resting on a piece of wood laid

on the bottom of that vessel. Very hot water is then poured into the vessel until it reaches the level of the milk in the bottles. It is set on the fire until the water boils. Then it is taken off and set on a hot sur-face or near the stove for a quarter of an hour. After that it is moved to the washing basin, where the hot water in it is replaced by cold, the water being kept running into it for five minutes; finally the bottles are left in the cold water, closed, until they are needed.

Q — Thank you. And I wish you could help us in another aspect of economy in kitchen expenses. What is the method by which the housewife can make sure that eggs are fresh, so that she is not forced to buy spoiled ones? You know, no doubt, that the prices of eggs — this essential food — have risen very high.

A — It is difficult for a lady to recognize a fresh egg with the naked eye. That requires expe-rience and practice. But inside the egg, at its lower end, there is a hollow known as the air

chamber, and the fresher the egg, the smaller this hollow. You can recognize an old egg by the sound its large air chamber makes when you shake it in your hand.

Q — And the water-and-salt method? I have heard of it before.

A — That is the specific-gravity method — that is, the ratio of the egg's weight to the weight of an equal volume of salted water. If we add to a liter of water 125 grams of salt, or the equivalent of about half an uqiyya, we obtain a specific gravity close to the specific gravity of an egg. In this case an egg one day old can be recognized: if it is placed in this liquid, it remains lying horizon-tally at the bottom of the vessel.

Q — And if it is older than that?

A — Its weight will decrease by about a gram each day. And you can recognize fresh eggs if they rise in the salted water, for they usually float on the surface of the water.

Q — And what is the best season for preserving eggs?