Diophantus in Harpers Dictionary of Classical Antiquities（Διόφαντος). A mathematician of Alexandria, who, according to the most received opinion, was contemporary with the emperor Julian. This opinion is founded upon a passage of Abulfaraj, an Arabian author of the thirteenth century. He names, among the contemporaries of the emperor Julian , Diophantes (for Diophantus) as the author of a celebrated work on algebra and arithmetic; and he is thought to have derived his information from an Arabic commentator on Diophantus, Muhammed al Buziani, who flourished about the end of the eleventh century. The reputation of Diophantus was so great among the ancients that they ranked him with Pythagoras and Euclid. From his epitaph in the Anthology the following particulars of his life have been collected: that he was married when thirty-three years old, and had a son five years after; that the son died at the age of forty-two, and that Diophantes did not survive him above four years; whence it appears that Diophantus was eighty-four years old when he died. Diophantus wrote a work entitled Ἀριθμητικά, in thirteen books, of which only six remain. It would seem that in the fifteenth, and even at the beginning of the seventeenth, century all the thirteen books still existed. The arithmetic of Diophantus is not merely important for the study of the history of mathematics, but is interesting also to the mathematician himself from its furnishing him with luminous methods for the resolution of analytical problems. We find in it, moreover, the first trace of that branch of the exact sciences called algebra. There exists also a second work of Diophantus, on Polygon Numbers (Περὶ Πολυγόνων Ἀριθμῶν). He himself cites a third, under the title of Πορίσματα, or Corollaries. A good edition of Diophantus is still that of Fermat (Toulouse, 1670). It is based upon that of Meziriac (Paris, 1621), with additions. A valuable translation of the Arithmetica into German was published by Otto Schulz (Berlin, 1822). The latest edition of the text is by Tannery (Leipzig, 1893). On the so-called Diophantine Analysis, see Euler's Algebra, pt. ii. The reader is referred to Heath's Diophantos of Alexandria (1885).
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