1. Poggendorff's. Annalen, vol. lxxix 376–376. I have already enunciated this view in my first memoir on the Mechanical Theory of Heat, having, in fact, inserted the following in a notewhich has reference to the diminution of the cohesion of water with increase of temperature:—“Thence it follows, also, that only part of the quantity of heat which water receives from without when heated, is to be regarded as heat in the free state, while the rest is consumed in diminishing the cohesion. In accordance with this view is the circumstance that water has so much higher a specific heat than ice, and probably also than steam.” At that time the experiments of Regnault on the specific heat of the gases were not yet published, and we still found in the text-books the number 0.847, obtained by De la Roche and Bérard, for the specific heat of steam. I had, however, already concluded, from the theoretical grounds which are the subject of the present discussion, that this number must be much too high; and it is to this conclusion that the concluding words, “and probably also than steam,” refer