Copy letter from James Hopwood Jeans, Secretary of the Royal Society; to Professor [John Cunningham] McLennan, FRS Refers to [E. F.] Burton and [E.] Bishop's paper, 'The law of distribution of particles in colloidal solution', that Professor [John Cunningham] communicated to the Society. Explains that the referee is of the belief that the authors' 'modification of Perrin's formula seems to be unsound'. Returns the manuscript and urges Professor McLennan to get the authors to consider this criticism. 13 January 1921