The Whetstone of Witte, whiche is the seconde parte of Arithmeteke: containing the extraction of rootes; the cossike practise, with the rule of equation; and the workes of Surde Nombers (London, 1557). This was the book in which the equals sign was introduced within a printed edition.[2] With the publication of this book Recorde is credited with introducing algebra into the Island of Britain with a systematic notation.[5][6] A medical work, The Urinal of Physick (1548), frequently reprinted.[7]