_Egg Substitutes._--Many products have been put upon the market of a yellow color and containing protein under the guise of eggs. There is a number of so-called egg powders offered for making cakes, etc., which contain no egg at all. They are composed of other forms of protein matter, generally casein from milk, and colored to resemble the egg in tint. Starchy substances are also colored and sold as egg powder. These substances may be regarded as adulterations when sold under the name or in the guise of an egg product. There are no other adulterations of eggs of any consequence practiced except the simulation of egg material by such products as those just mentioned. _Poisonous Principles in Eggs._--While fresh eggs for most people form a food product entirely devoid of danger, nutritious and easily digestible, eggs may easily become injurious and even poisonous. According to experiments made by Bouchard (Scientific American, August 11, 1896, page 95), even fresh eggs, unless the sanitary conditions in which the fowls live are well cared for, may become very poisonous. The fowl producing eggs, as a rule, is not a cleanly animal, and this is especially true of the duck. Thus injurious organic material rich in microbes may contaminate the egg and the microbes may penetrate the shell thus rendering the egg unsuitable for consumption. Eggs contaminated in this way have given evidence of toxic phenomena even in a fresh state. Experiments have shown too that the food material of eggs if directly injected into the blood of an animal produces toxic effects whereas if injected into the stomach no unfavorable effects are produced. Egg albumin, that is, the albumin of the white of the egg, when fed in considerable quantities to animals partially escapes digestion and thus becomes a source of irritation and even of poisoning. There are many people who are remarkably sensitive to the influence of eggs and those who possess this idiosyncrasy are injured even by eggs which are perfectly harmless to other people. A large number of species of injurious microbes which infect eggs have been identified. These even are found in fresh eggs in the unsanitary conditions above mentioned. Eggs kept for a long while in cold storage or decayed in any way are extremely injurious. Fortunately decayed eggs are self protecting since they can only be eaten by accident. If, however, decayed eggs be eaten in diluted form by mixing with other foods they may be eaten without their characteristic odor or taste being known and thus great injury arises. It is advised in all cases where eggs are to be kept for some time even in cold storage to varnish them with some substance impenetrable to air. For this purpose, as has already been mentioned, soluble glass, which is chemically a silicate of soda, has been found extremely effective. Any of the varnishes which make the shell of an egg air tight tends to restrain the activities