Where compulsory legislation is in force it is generally required that these by-products be heated to a temperature of at least 176° F. This is done so as to destroy effectually the organisms of tuberculosis, and especially to permit of the utilization of the so-called Storch test,[1] which enables a person to determine quickly whether milk or whey has been heated or not. [1] Storch (40 Rept. Expt. Stat., Copenhagen, 1898) has devised a test whereby it can be determined whether this treatment has been carried out or not; milk contains a soluble enzyme known as peroxidase which has the property of decomposing hydrogen peroxid. If milk is heated to 176° F., (80° C.) or above, this enzyme is destroyed, so that the above reaction no longer takes place. If potassium iodide and starch are added to unheated milk and the same treated with hydrogen peroxid, the decomposition of the latter agent releases oxygen which acts on the potassium salt, which in turn gives off free iodine that turns the starch blue. =Cleaning utensils.= Various processes are applied to dairy utensils to cleanse them. In removing visible dirt and foreign matter, much of the bacterial life is mechanically eliminated, but most of the cleaning processes fail to destroy the germ life in these utensils. In rinsing, washing, or even scalding, the water is not applied at a sufficiently high temperature to destroy effectively the bacteria. These processes are primarily used for the removal of dirt and other matter. To facilitate such removal, washing powders of various kinds are frequently employed; some of these possess considerable disinfecting action. All utensils after cleansing should be thoroughly rinsed in clean, hot water. Even where no further treatment is given, a careful cleaning may so reduce the germ content on the inner surface of utensil as to render contamination therefrom relatively unimportant. Most of the contamination in a well cleaned utensil comes from the cracks and angles, which permit of the collection of the dirt. If these are properly attended to, thorough cleaning and rinsing alone will accomplish much.