10 months. Thus it appears that more than three fourths of all the eggs which are stored remain in storage over 4 months, but practically none remain in storage longer than 10 months. The average length of storage of eggs was found to be 5.9 months. The total cost of storage was estimated at 0.57 cent per dozen per month or 3.5 cents per dozen for the average length of storage. In general the stored eggs must sell, as Professor Taylor has pointed out, at a sufficient advance on their original price to pay all the costs of storage, and in addition " enough profit to induce a business man to give his attention to this business instead of doing something else."

In the case of eggs as of other perishable foods the introduction of cold-storage facilities has changed considerably the relative monthly consumption and made it more uniform throughout the year. Cold storage also tends toward greater uniformity of prices throughout the year, keeping up prices in the season of maximum production, and diminishing somewhat the increase of price which occurs at the season of natural scarcity. The cold-storage industry tends to raise the average or annual price level both because the costs of storage must in the long run be paid by the consumers and because as the result of the steadying effect of cold storage upon prices a larger proportion of consumers now use eggs throughout the year, so that there is a much larger volume of business during the season of high prices. So far as this last factor is concerned it may fairly be considered that the standard of living is raised with the cost.

The conclusion drawn from the statistical investigation conducted by the United States Department of Agriculture (19091911) was that there is no just ground for complaint against the men who keep foods in cold storage except in so far as they sometimes speculate. Since the power to withhold goods from the market obviously constitutes a temptation to try to raise prices by creating an artificial scarcity (or exaggerating a scarcity which already exists), it was recommended that storage ware

houses be required to make monthly reports to the government and that official estimates of the quantities of foods in storage be made public each month somewhat as in the case of the government crop reports.

This is now largely accomplished and about half of the states also have laws directly regulating the operations of cold-storage warehouses. These laws usually require that such warehouses and their records shall be open at all times to inspection and that any food placed in cold storage for 30 days or more shall be labeled as cold-storage food and the package be branded with the date it was received by the storage warehouse and the date it was delivered. Usually also special permission must be obtained if it is desired to extend the period of cold storage of any food for a longer time than twelve months.

Effect of cold storage upon eggs. Meats and poultry when stored are often kept hard frozen, but this of course is not practicable for eggs. Eggs are best stored at temperatures just above their freezing point, which of course is below that of water. From 29° to 32° F. is the usual temperature for egg storage. At such temperatures the eggs, if kept in moist air, become musty or moldy. To prevent this, the air in well-regulated storage rooms is kept moderately dry, as the result of which moisture evaporates through the shell and the contents of the egg shrink, the size of the air chamber becoming larger. This condition is detected by candling, as already explained. Other results of long storage are an increased tendency of the egg albumen to adhere to the shell membrane, and sometimes a slight crystallization of certain of the components of the egg. One of the earliest prosecutions by the Government after the Food and Drugs Act became effective in 1907 was against a dealer in Washington, D. C., for selling eggs "misbranded in that they were sold as strictly fresh when not so," the evidence against the eggs being "that the albumen clung to the shell membrane, that the air chamber was greatly enlarged, and that minute rosette crystals

were found in the albumen and larger rosette crystals in the yolk."

During storage the white of egg loses moisture not only by evaporation through the shell, but also by an osmotic transfer of water from the white to the yolk. Greenlee has studied this point quantitatively and proposed a formula by means of which the length of time an egg had been in storage could be judged from the water content of the white if the temperature and humidity of the storage room were known.

As a result of the transfer of water from the white to the yolk of the egg, the latter expands somewhat and the membrane which separates the yolk from the white is stretched and weakened and may break and permit a spreading of the yolk into the white, especially if the egg is carelessly handled.

These results of storage may interfere seriously with the appearance and behavior of the eggs when boiled or poached, and eggs showing these properties are rated considerably below fresh eggs in market value, but it should be noted that none of these effects is indicative of decomposition or unwholesomeness or indeed of anything but purely physical changes.

That slight chemical changes may occur during the time that eggs are ordinarily held in storage seems probable in view of the somewhat different flavor and strength of white in fresh and storage eggs. Normally the change in flavor is no different from that which takes place in a much shorter time when the eggs are kept under household conditions. Just why the white of the storage egg shows somewhat less strength than that of the fresh egg is not entirely clear, but may be due to slight selfdigestion ("autolysis") such as occurs in animal organs and tissues generally when removed from the body and protected from the action of microorganisms.

The slight changes in flavor and in behavior on cooking and the fact that storage eggs are sometimes fraudulently sold as 1 Journal of the American Chemical Society, Vol. 34, page 539.

fresh in the retail trade are sufficient to explain the prejudice against cold-storage eggs which exists among many if not most consumers. But these properties should not be confused with those which are indicative of decomposition and unwholesomeness. As regards wholesomeness, there is no presumption against the cold-storage egg as such. In general, storage eggs may be regarded as less desirable than those which are in reality "strictly fresh," but superior to many of the so-called "fresh" eggs which have not had the benefit of refrigeration.

Many species of organisms, both bacteria and molds, have been found in decaying eggs. In general the spoilage which takes place rapidly at high temperatures is apt to be due chiefly to bacteria, while the mustiness which develops slowly at low temperatures is often due more largely to molds. An initial infection with bacteria may occur while the egg is still within the oviduct of the hen; or organisms may gain entrance after the egg is laid, especially if it be allowed to lie in an unclean nest. The properties of the white and yolk with reference to bacterial growth are summarized by Buchanan as follows: Egg white has been shown to possess distinct antiseptic properties. Many species of bacteria are quickly destroyed when mixed with it. This is not true of the yolk, for this is a favorable growth medium for many species of bacteria. It is not probable that this bactericidal property of egg white persists indefinitely, but it is doubtless responsible for the fact that the egg keeps as well as it does.

Certain types of spoilage are due to developing embryos and are therefore avoided in the case of infertile eggs.

Frozen and Dried Eggs

Freezing and drying are the two general methods of preserving eggs when removed from their shells. Pennington and also Stiles and Bates, of the United States Department of Agricul

1 Bacteriology, page 508.

ture, have made special investigations of frozen and dried eggs and the following is based chiefly on their findings. Since the centers of egg production and egg consumption are now so widely separated, it is believed that, properly conducted, the freezing and drying of eggs is an industry which is economically desirable, especially so long as the prevalent methods of handling bring to the dealers in the producing sections great numbers of eggs which are wholesome but not available for long hauls. Another important consideration is that frozen eggs can be stored at very much lower temperatures than can eggs in the shell.

As Pennington points out, the handling of eggs which have been removed from their shells is somewhat analogous to the handling of milk and, like the milk industry, should be characterized by the most scrupulous cleanliness throughout. As in the case of milk, the sources of contamination are best demonstrated by bacteriological methods and can in the main be eliminated by the adoption of such precautions as a knowledge of sanitation would suggest cleanliness of surroundings and workers, frequent cleansing and drying of the fingers, use of appliances and containers which have been sterilized by means of live steam, prompt freezing or drying of the egg after removal from the shell, etc. A complicating factor in this industry is that eggs do not come directly from the farm to the breaking establishment and even though the eggs be sorted by candling before going to the breakers, some of the eggs which have passed the candler prove to be distinctly bad when broken. In legitimate establishments, such an egg is rejected and the receptacle into which it was broken as well as the fingers of the breaker are rinsed before being used again. Mere rinsing, however, is not sufficient to prevent the contamination of the next egg, since large numbers of bacteria from the bad egg remain in the receptacle even though it looks and smells clean. Pennington recommends that all the fittings of the room in which eggs are broken and all the appliances and receptacles used be of metal