A new form of calorimeter suitable for determining heats of solutions, with an application to worked and annealed metals

In the course of a study of cold-worked metals it has been found desirable that some means should lie devised for measuring the amount of energy stored in a metal when it is deformed beyond the elastic limit. During this process of cold-working a large part of the work done is converted into beat, but the change in properties of the metal is such as to indicate that its potential energy has been increased. The increase is known to be relatively small, and therefore difficult to measure. It should be possible to determine it by dissolving the cold-worked metal in a suitable solvent and finding the beat of solution, any difference between the result and the beat of solution of the same metal in a fully annealed or unworked condition then representing the increase of potential energy. such a method has not hitherto been applied with success, on account of the insufficient accuracy of the usual calorimetric methods, and the object of the present paper is to describe a calorimeter on the continuous flow principle originally due to callendar, having an increased sensitivity when used for such experiments. A few measurements of the beat of solution of cold-worked metals, and of the same metal in the annealed condition, are included. The results show that the potential energy stored in cold-working amounts, for the metals examined, only to about 1 per cent, of the heat of solution.Some Earlier Types of Calorimeter . The heat of solution of metals was a subject investigated by Salt* and Baker. Baker employed a calorimeter in the form of a thin glass beaker of 500 c. c. capacity. This was supported inside a highly polished nickeled vessel, and the whole was screened from the influence of external fluctuations of temperature by surrounding it with a copper water jacket. The water was kept in motion by means of a stirrer. A copper lid was used to cover this enclosure. Such an apparatus has a considerable water equivalent, and this was determined by the method of mixtures.