History of diabetes further clarified in 1921, when Sir Frederick Grant Banting and Charles Herbert Best repeated the work of Von Mering and Minkowski, and went further to demonstrate they could reverse induced diabetes in dogs by giving them an extract from the pancreatic islets of Langerhans of healthy dogs. The islets of Langerhans was discovered in 1869 by an anatomist named Paul Langerhans. He identified the keys cells in the pancreas which produce the main substance that controls glucose levels in the body. Banting, Best, and colleagues (especially the chemist Collip) went on to purify the hormone insulin from bovine pancreases at
Islets of Granada for the residents and for tourists. Hotels and shops are established on some of the islets, and boating tours are available. The fort of San Pablo is located on the islets in Lake Nicaragua. The fort of San Pablo was built in order to protect the city of Granada from Pirates in the 18th century. The San Pablo Fort on the Islets has witnessed the battles and conflicts endured during the Colonial Period. Many residents of the islands were forced to relocate to the mainland in the 1990s after having lived there for several generations. During Somoza's dictatorship, members of