Paper, 'An account of an experiment made on Thursday the last day of June 1720 before the Royal Society to shew by a new proof that bodies of the same bulk do not contain equal quantities of matter, and therefore that there is an interspers'd vacuum' by J T [John Theophilus] Desaguliers Desaguliers describes an experiment made on 30 June 1720. He begins: 'I took 3 pound of Mercury, which by measure fill’d three times a small glass jar exactly full, and pour’d it into a thin Florence flask.' Subject: Physics Read at the Royal Society on 7 July 1720 Published in Philosophical Transactions as 'An account of an experiment made on Thursday the last day of June, 1720. Before the R. Society, to shew by a new proof, that bodies of the same bulk do not contain equal quantities of matter, and' therefore that there is an interspers'd vaccuum. by J. T. Desaguliers' 1720