Carl Linnaeus was well aware of the scientific value of his correspondence. By the time of his death in 1778 he had received more than 3,000 letters from Europe, America, Asia and Africa. These were received from natural history scientists like himself, as well as from his students on different expeditions all over the world. Linnaeus had more than 600 correspondents! Together with the 2,000 letters preserved from Linnaeus himself, this material represents an invaluable source of information for scholars of science as well as of history.