Page:Outlines of Physical Chemistry - 1899.djvu/159

 THE CALORIMETER

��vessel, furnished at the bottom with a stopcock tube or with a valve. If a flask be used it is placed at the side of the calorimeter; if the metallic reservoir be used it is placed laterally above the calorimeter as shown in fig. 36. When the temperature of the two liquids has become constant, and is as nearly as possible the same for the one as for the other, they are mixed in the calorimeter — by pouring from the flask or by opening the stopcock or valve of the metallic reservoir. The stirrer is then set in

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��motion, and the highest temperature registered by the thermometer is noted. The number of calories evolved in the process is equal to the caloric capacity of the calorimeter and its contents multiplied by the observed change of temperature.

The caloric capacity of the calorimeter is composed of the water equivalent of all those parts of the apparatus which suffer a change of temperature, viz. the calorimeter vessel, the immersed part of the thermometer and of the

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