Summary from Wikipedia

Rask traveled extensively to study languages, first to Iceland, where he wrote the first grammar of Icelandic, and later to Russia, Persia, India, and Ceylon (now Sri Lanka). Shortly before his death, he was hired as professor of Eastern languages at the University of Copenhagen. Rask is especially known for his contributions to comparative linguistics, including an early formulation of what would later be known as Grimm's Law. He was elected as a member to the American Philosophical Society in 1829.[3]