Letter from W C D [William Cecil Dampier] Whetham, Upwater Lodge, Cambridge, to [Joseph] Larmor Whetham thinks that Larmor's ideas on osmotic pressure relations is right. He sketches a curve of pure water and salt crystals, with a straight dotted horizontal line representing pressure, at a tangent to the solutions curve. For soluble salts the curve would be more complicated he believes, giving another sketch as a possible example. Whetham thinks that no-one has measured the osmotic pressure of strong solutions, but there is data on vapour pressure. He notes his intention to investigate osmotic pressure by logarithmic relation, when he gets time. He concludes by stating how to work out the lowering of solubility of one slightly soluble salt by the addition of another. 25 April 1904