James Lind was a Scottish physician. He was a pioneer of naval hygiene in the Royal Navy. Scurvy is a disease now known to be caused by a Vitamin C deficiency, but in Lind's day, the concept of vitamins was unknown. Vitamin C is necessary for the maintenance of healthy connective tissue. He divided twelve sailors who were sick with scurvy into two groups. They all received the same diet but, in addition, group one received two oranges and a lemon every day, while group two did not. The treatment of the first group stopped after six days when they ran out of fruit, but by that time one sailor was fit for duty while the others had almost recovered. Every sailor in the group that did not receive the fruit remained sick. By conducting the first clinical trial (in 1747), James Lind helped develop the theory that citrus fruits help to cure scurvy. What are the Independent Variable Dependent Variable Standardized variable Control Group Experimental Group