Scurvy

' Take your hand from my cloak, my Lord Duke, and I may answer you,' said Christian. ' I have a scurvy touch of old puritanical humour about me. I abide not the imposition of hands—take off your grasp from my cloak, or I will find means to make you unloose it.'

From Walter Scott's "Peveril of the Peak".  The surgeon that observed that citris fruits had a beneficial impact on the incidence of scurvy began his experiments on May 20, 1747 (http://www.rampantscotland.com).  Edinburgh born James Lind's pushed for several improvements to naval hygeine, including ventilation, fumigation below deck, and distilling fresh water from sea water.