Secretin
Secretin was the first hormone to be identified. In 1902, William Bayliss and Ernest Starling were studying how the nervous system controls the process of digestion. It was known that the pancreas secreted digestive juices in response to the passage of food (chyme) through the pyloric sphincter into the duodenum. They discovered (by cutting all the nerves to the pancreas in their experimental animals) that this process was not, in fact, governed by the nervous system. They determined that a substance secreted by the intestinal lining stimulates the pancreas after being transported via the bloodstream. They named this intestinal secretion "secretin". Secretin was the first such "chemical messenger" identified. This type of substance is now called a hormone, a term coined by Bayliss in 1905.
Gladys Anderson Emerson
From 1933–1942 she was a research associate at the Institute of Experimental Biology at the University of California at Berkeley, working with Herbert McLean Evans. Herbert Evans had identified and named Vitamin E in 1922, but Gladys Emerson was the first person to isolate it, by obtaining alpha-tocopherol from wheat germ oil. In 1940, she and her husband divorced.