I. On the method of condensation in calorimetry

A substance at the initial temperaturet 1 ° of the atmosphere, suddenly immersed in a saturated vapour at the higher temperaturet 2 °, abstracts from it a quantity of heat equal to WC(t 1 ° ‒t 2 °), where C is the thermal capacity of the substance between the limitst 1 ° andt 2 °, and W its weight. There is then a weightw of the vapour precipitated, so that WC(t 2 ° ‒t 1 °) =w λ, λ being the latent heat of the vapour.