Date of this Version
Joly, in 1886, and Bunsen, shortly afterwards, described two similar pieces of apparatus intended to determine the specific heat of substances by means of the condensation of water vapor upon them. The name given by Bunsen to this apparatus and adopted here is vapor calorimeter. Bunsen also intended his instrument to be used in the determination of the latent heat of vaporization of various liquids, and it is the object of the present paper to describe experiments testing the steam or vapor calorimeter in this direction. A rough experimental instrument was first constructed, combining to a certain extent the principles of Joly and of Bunsen, and this proving fairly satisfactory, an apparatus was made by a local tinman, which, while much less expensive than Joly's final form, worked in a very satisfactory manner.