Brunner's missing 'Aha experience' delayed progress in diabetes research by 200 years.

In 1889, the pancreatectomy performed on a dog by Joseph von Mehring and Oskar Minkowski led to the discovery of the pancreatic origin of diabetes disease. Already 200 years before, Johann Conrad Brunner had successfully performed eight pancreatectomies on dogs and had precisely described the symptoms of polyphagia, polyuria, and polydipsia. He did not, however, recognize the association with the diabetes disease and thus missed an opportunity to accelerate the course of diabetes research by 200 years.