Читать книгу Foods and Their Adulteration - Harvey Washington Wiley - Страница 128

—The various fats give different degrees of heat when mixed, under certain conditions, with strong sulfuric acid. It is possible to determine the approximate degree of the adulteration of lard by applying this test. The operation is a simple one and is conducted in the apparatus shown in Fig. 11. A common test tube about 24 cubic centimeters in length and 5 cubic centimeters in diameter is hung as indicated in the figure, provided with a stopper carrying a thermometer in the center with a bent glass rod stirrer passed loosely through the stopper on the side and a funnel for the introduction of the acid on another side of the thermometer. A coil which is on the stirring rod is so arranged as to permit the bulb of the thermometer to pass through its center.

Fig. 11.