The object of the researches described in this paper, was to carry out with reference to amalgams the investigations relative to alloys contained in a former paper. In comparing the results of theory and experiment in the manner followed in the former paper, the conducting power of mercury itself was a constant, which it was essential to know. The figure given in the former paper was mercury = 677, on the scale silver = 1000. On adopting in the first instance this value of the conducting power of mercury, the results obtained with alloys, which consisted mainly of mercury, appeared very anomalous; it seemed as if a very small per-centage of even the best conducting metals reduced immensely the conducting power of mercury. But it was suggested to the authors, that the apparently high conducting power of mercury obtained by their method, was probably due to the transference of heat by convection; that the real conducting power of mercury for heat was low, like its conducting power for electricity; that the other metal, contained in small quantity in the amalgam, acted by rendering the amalgam viscous, and thereby interfering with the transference of heat by convection, and that the low conducting power of mercury would show itself on merely inclining the vessel used in the experiment, so that the box containing the warm water should be higher than the other. Experiment confirmed this view. As the apparent conducting power of mercury was found continually to decrease with an increase in the inclination of the vessel, it was found necessary, in order to obtain correct results, to arrange so that the bar-shaped box containing the mercury or fluid amalgam was actually vertical in the experiment. In this way the authors obtained for mercury the figure 54, on the same scale as before. It is worthy of remark, that mercury comes out the worst conductor of all the metals tried, the figure for bismuth, which had previously been the lowest, being 61. This is in analogy with water, also a fluid, the conducting power of which is known to be excessively low. The conducting power of the more fluid amalgams determined by experiment with the box vertical, proved to be in all cases nearly the same as that of pure mercury, in conformity with the law mentioned by the authors in their former paper, that alloys in which there is an excess of the number of equivalents of the worse conducting metal, over the number of equivalents of the better conductor, do not sensibly differ in conducting power from the worse conductor alone. In the case of amalgams generally, the conducting power obtained by experiment was found to agree pretty closely with the number calculated from the per-centages and conducting powers of the component metals.