Referee's report by Hugh Longbourne Callendar, on a paper 'On the inversion points for a fluid passing through a porous plug, and their use in testing proposed equations of state' by Alfred William Porter Sectional Committee: Physics and Chemistry Not recommended for publication in the 'Proceedings of the Royal Society of London'. More suited for the Physical Society [Institute of Physics] than the Royal Society. The paper contains no experiments or practical applications. Refers to work of Van der Waals [Johannes Diderik van der Waals], Dieterici and Rose. [Not published] Endorsed on verso as received 14 February 1906. 10 February 1906