Referee's report by Syndey Chapman, on a paper 'Some experiments on thermal diffusion' by T L Ibbs Sectional Committee: Physics Recommended for publication in the 'Proceedings of the Royal Society of London'. Refers to work by Chapman and Dootson, on whose work the current paper builds. Appends a note which he would like printed with the paper, if the author does not object. [Published in the 'Proceedings of the Royal Society of London' A, 1921] Endorsed on recto as received 29 March 1921. 26 March 1921