Referee's report by Alfred William Porter, on a paper 'Physico-chemical determinations at high pressures by optical methods' by Walter Wahl Sectional Committee: Physics and Chemistry Recommended for publication in the 'Philosophical Transactions of the Royal Society'. Suggests adding a preparatory sentence, as otherwise the paper begins very abruptly. Suggests omitting some of the conclusions. [Published in the Philosophical Transactions of the Royal Society, 1913] Endorsed on verso as received 11 May 1912. [May 1912]