This sophistication is not common in this country. Horse flesh is detected by testing for glycogen, which is present in it in larger quantities than in other meats.
Courley & Coremon’s Test.—Boil 50 grams of the meat for a half hour with water, strain, and to a portion of the filtrate add a few drops of potassium iodid-iodin solution (potassium iodid 0.4 gram; iodin 0.1 gram; water 20 cc.). If considerable horse meat is present the glycogen will color the liquid dark brown, which disappears on heating, but returns on cooling.
EGGS
It sometimes happens that one wishes to know the age of eggs without opening them.
Delarne’s Test.—Place the egg in a 10 per cent solution of common salt. Perfectly fresh eggs sink to the bottom. Those remaining immersed, but suspended in the liquid, are at least three days old, while those rising to the surface and floating are more than five days old. The older the egg, the higher it floats and the more it will stand on end. This test is not applicable to eggs that have been preserved.
Hold the egg between a bright light and the eye, and if the air chamber is small, and no dark spots but instead a rather uniform rose-colored tint is seen, the egg is fresh. If the contents appear cloudy and the air chamber larger, the egg is not fresh. The darker the contents of the egg the older it is.