Note 31 — Chapter IV · Application of the Idea of Substance in Chemistry.

See the answer to Sir William Hamilton’s objections, at the end of the last chapter. Since we are thus warned by a sound view of the nature of science, from considering chemical affinity as having any hold upon imponderable elements, we are manifestly still more decisively prohibited from supposing mechanical impulse or pressure to have any effect upon such elements. To make this supposition, is to connect the most subtle and incorporeal objects which we know in nature by the most gross material ties. This remark seems to be applicable to M. Poisson’s hypothesis that the electric fluid is retained at the surface of bodies by the pressure of the atmosphere.