In the great majority, at least, of investigations (experimental or mathematical) connected with conduction of heat, it has been assumed that the known changes of specific heat of metals do not require to be taken into account. Thus Ångström says, even in his paper on the Change of Conductivity with temperature (Pogg. 118, 1863):—“Da indess diese Veränderungen, soweit man sie kennt wenigstens innerhalb der bei den Beobachtungen vorkommenden Temperaturgränzen, nicht bedeutend sind, …,… so müssen dieselben den Werth des Wärmecoefficienten nur unbedeutend afficiren können.”