Referee's report by Hugh Longbourne Callendar, on a paper 'The vapour pressure in equilibrium with substances holding varying amounts of moisture' by Professor Frederick Thomas Trouton and Miss B Pool Sectional Committee: Physics and Chemistry Recommended for publication in Philosophical Transactions in full and without modification. All the illustrations should be reproduced but he would prefer to see the curves reproduced in the text on a reduced scale. The vertical scale of figure III, part II should be reduced as compared with the horizontal. The experimental result that the ratio of the vapour pressure to the saturation pressure for a given weight of water absorbed is independent of the temperature agrees with the general law of solutions. This might be stated more clearly and the method might be extended to other liquids and absorbents with a view to establishing analogous molecular relations to those existing for solutions. [Published in Proceedings of the Royal Society A, 1906]. Endorsed on verso as January 1906