Simon Maddrell writes about J. A. Ramsay's 1954 publication `Active transport of water by the Malpighian tubules of the stick insect Dixippus morosus (Orthoptera; Phasmidae).' A pdf file of Ramsay's paper can be accessed as supplemental data
Through most of his career, Arthur Ramsay was fascinated by matters osmotic. In the period after the Second World War, he worked on osmotic relations of the earthworm (Ramsay,1949a), developing typically novel methods for measuring the melting-point and sodium content of minute quantities of fluids (Ramsay, 1949b, 1950). However, in the early 1950s, Ramsay started working on insect Malpighian tubules. He soon found that the tubules secreted potassium ions into the lumen against an electrochemical gradient, showing that this transport was an active one. This led Ramsay to the attractive idea that “the secretion of potassium (together with some anion) into the tubule will set up an osmotic...
