Who was the Scottish mathematician, physicist and astronomer who is credited for introducing "natural" logarithmic function?
Napierian logarithm:  Napier did not introduce this "natural" logarithmic function, although it is named after him. John Napier: John Napier of Merchiston ( ; 1 February, 1550 – 4 April 1617); also signed as Neper, Nepair; nicknamed Marvellous Merchiston) was a Scottish landowner known as a mathematician, physicist, and astronomer.
John Napier