The assumption that the gas molecules are aggregates of material points, in the sense of Boscovich, does not agree with the facts. But what else are they? And what is the ether through which they move?

Ref: Lord Salisbury, Presidential Address to the British Association meeting at Oxford (Aug, 1894) "Address by the Most Hon. The Marquis of Salisbury, K.G., D.C.L., F.R.S., Chancellor of the University of Oxford, President", Report of the Sixty-fourth Meeting of the British Association for the Advancement of Science held at Oxford (August, 1894) p. 8.