Letter from [Randal Mowbray Thomas Rawdon Berkeley, 8th Earl of] Berkeley, Berkeley Castle, Gloucestershire, to Joseph Larmor He thanks Larmor for his letter and he sends the paper. The disagreement is in the note at the end of the paper and he points out that if their conclusion is valid, then Porte's method of deriving the osmotic pressure from vapour pressure must be faulty. Berkeley's experimental results, soon to be published give excellent agreement between direct and indirect methods. 9 September 1918