Referee's report by Ralph Howard Fowler, on a paper 'The equilibrium of heterogeneous systems including electrolytes. Part I. Fundamental equations and phase rule' by John Alfred Valentine Butler Sectional committee: Chemistry Recommended for publication in Proceedings, although there is not much 'original matter' in the paper. [Published in Proceedings of the Royal Society A, 1926]. Endorsed on verso as received 9 June 1926. June 1926