Criticism of Calorimetric Conceptions

Abstract

The unit of quantity of heat is usually defined as the quantity of heat which is necessary to heat 1 kg of water by 1 °C, or, if greater accuracy is required, from 0° to 1 °C. The quantity n units of heat, is, then, the quantity which contains the said unit n times. It is usually added by way of explanation that, in order to heat n kg of water from 0° to 1 °C, “obviously” n times the quantity of heat necessary to heat 1 kg through the same change of temperature is necessary, since, in the former case, “the same process” takes place n times. If we show that, by the cooling of 10 kg of water by 1 °C, 1 kg can be heated by 10 °C or 2 kg by 5 °C or 10 kg by 1 °C, then it follows, so far as this is exact, that the different single centigrade degrees are equivalent. It is then permissible to measure the quantity of heat “necessary” for the heating of m kg of water by u°C, by the product mu. It would be strange if anyone accustomed to more precise analysis of his conceptions who read this customary explanation as a student, or advanced it as a teacher, did not experience an intense logical discomfort.