on the same day pcrt:>ii>^* 'n canon law, ami it bears the title: "Die Bination iiacli ilirer geschichtlichen Eiitwicklung uiul nai-h cleiii heutinen Hecht" (Ratis- l)on, 1S74). After lS7cS Neher eilili'd tlie statistieal "Personalkatalop" of his own dioeesc of Hottenbiuf;, and was one of the principal eontrilmlors to the sec- ond edition of I he Kirclieidexilioii of Welzer and Welte. For this work he wrote no fewer than 235 arti- cles, or greater parts of articles. Their content is chiefly matter relating to church history, or to ecelesi- iu-itical statistii's; liis best articles are those relating to the latter suliject ; those of purely historical interest a.K often imperfect.
J. P. KiRSCH.
NSlaton, ArcrsxE, famous French surgeon; born in I'aris, 17 June, 1807, d. there 21 Sept., 1S73. He made his medical studies in Paris, graduating in 1S3G with a thesis on tuberculous affections of bones. All his subsequent university career was passed at Paris. After the publication of his "Traite dcs tumeurs de la mamelle" he became agrege in 1839. In 1851 he be- came professor of clinical surgery with a thesis which attracted wide attention and was translated into Ger- man the following year. As a member of the surgical staff of the St. Louis Hospital, he devised a number of original surgical procedures and operations, was the first to suggest the ligature of both ends of arteries in primary and secondary hemorrhage, and developed several phases of plastic surgery. The Nelaton probe with the porcelain knob, which he invented, was suc- cessfully used b}' him in Garibaldi's case, in 1862, to locate a bullet in the ankle joint. Some of his sugges- tions ■with regard to operations were important ad- vances in abdominal and pelvic surgery. He was, lastly, noted as a great teacher of surgery and a con- summate operator.
Pagel, the German historian of medicine, in his "Biographical Dictionary of Prominent Phy- sicians of the Nineteenth Century", says of Nelaton: "He was a man of very clear judgment, of ripe experience, of solid wisdom, and deservedly occupies a place as one of the greatest of French surgeons of the nineteenth century. " In 1863 he was elected a member of the Paris Academy of Medicine and in 1867 of the French Institute of Science, and became Sena- tor of the French Empire in 1868. His fame as a writer on surgery rests upon his "Elements of Surgical Pathology" (5 vols., Paris, 1854-60). The last vol- ume was completed with the collaboration of A. Ja- main. In 1867 Nelaton had an important share in preparing the "Report on The Progress of Surgery in France".
GcYON in Bulletins el Mimoires de la Roc, de Chir. (1876); B£cu\RD in Memoires de VAcadimie de Mid., XXXII; Gurlt, Biogr. Lex. der hervorrag. Aerzt.
J. J. Walsh.
Nemore, .Jordantjs (Jordanis) de, the name given in M.S.S. of the thirteenth and fourteenth centuries to a mathematician who in the Renaissance period was called Jordanus Nemorarius. A number of his works are extant, but nothing is known of his life. It is cus- tomary to i)lace him early in the thirteenth century. Emile Chasles, the geometrician, concluded from a study of the "Algorismus Jordani" that its author lived not later than the twelfth century. In the four- teenth century the EnglLsh Dominican Nicolas Triveth, in a chronicle of his order, attributed the "De ponderibus Jordani" and the "De lineis datis Jor- dani" to Jordanus Saxo, who, in 1222, succeeded St. Dominic as master general of the Friars Preachers. Since then, the identity of Jordanus Saxo with Jor- danus Nemorarius has been accepted by a great many authors; it seems difficult to maintain this opinion, however, a-s the Dominican superior general never adds de Nemore to his name, and the mathematician never calls himself Saxo. The literal translation of
Jordanus de Xcmorc (Giordano of Nemi) would indi- cate that he wa,s an Italian. Jordanus had a great vogue during the Miildle .\ges. In the "Opus Majus", iMider " Deconununibusnalurx", Roger Bacon <njole8 his " De iKinderibus", as well as a coninientary which had l>een written on it at that |)eriod. Tlionias Brad- wardine and the logicians who .succeeded him in (he school of Oxford likewise make a great deal of use of the writings of Jordanus. During the Renaissance his "De ponderibus" powerfully influenced the devel- opment of the science of statics.
The treatises composed by Jordanus de Nemore are: (1) "Algorismus", a theory of the elementary oper- ations of arithmetic. An " Algorithnius demonstratus Jordani" was printed at Nurenil.>erg in l.':3f, by Pe- treius for Johannes Schoner. The " Algorithmus" re- produced an anonymous MS. found among the papers of Regioraontanus. It was erroneously attributed to Jordanus, anil had really been composed in the thir- teenth century by a certain INIagister Gemardus (Duhem in "Bibliotheca mathematica", 3rd series, VI, 1905, p. 9). The genuine "Demonstrato Algo- rismi" of Jordanus, which E. Chasles had already ex- amined, has been rediscovered by M. A. A. Bjornbo (G. Enestrom in "Bibliotheca mathematica", 3rd series, VII, 1906, p. 24), but is still unpublished. (2) "Elementa Arismetica; " : this treatise on arithmetic, divided into dislindiones, was printed at Paris in 1496 and in 1514, to the order of Lefevre d'Etaples, who added various propositions to it. (3) "De numeria datis", published in 1879 by Treutlein ("Zeitschr. Math. Phys.", XXIV, supplem., pp. 127-66) and again in 1891 by Maximilian Curtze (ibid., XXXVI, "Histor. liter. Abtheilung", pp. 1-23, 41-63, 81-95, 121-138). (4) "De triangulis". — Jordanus himself gave this treatise the name of Philotechnes (Duhem in "Bibliotheca mathematica", 3rd series, V, 1905, p. 321; "Archiv fiir die Geschichte der Naturwissen- schaften und der Technik", I, 1909, p. 88). It was published by M. Curtze ("Mittheil der Copernicus- vereins fUr Wissenschaft und Kunst", VI — Thorn, 1887). (5) "Planispherium". — This work on map- drawing gives, for the first time, the theorem: The stereographic projection of a circle is a circle. It was printed by Valderus, at Basle, in 1536, in a collection containing the cosmographical works of Ziegler, Pro- c!us, Berosius, and Theon of Alexandria, and the "Planisphere" of Ptolemy. (6) "De Speculis", a treatise on catoptics, still unedited. (7) "De pon- deribus", or better, "Elementa super demonstrationem ponderis", a treatise on statics, in nine propositions, still unpublished, seems to have been composed as an introduction to a fragment on the Roman balance at- tributed to one Charistion, contemporary and friend of Philo of Byzantium (second century, B. c). This fragment has survived under two forms: (a) a Latin version directly from the Greek, entitled "De ca- nonio"; (b) a ninth-century commentary by the Arab mathematician Thabit ibn Kurrah, translated into Latin by Gerard of Cremona.
Most of the propositions of the "De ponderibus Jordani" are gravely erroneous. But the last offers a remarkable demonstration of the principle of the lever, introducing the method of virtual work for the first time in mathematical history. Towards the end of the fourteenth century, or the beginning of the fifteenth, an anonymous author expanded the demon- strations in Jordanus's treatise; in this enlarged form, the treatise, combined with the " De canonio ", is found in many MSS. under the title "Liber EuchdLs de ponderibus". There is also an anonymous commen- tary on the "De ponderibus", based on ideas appar- ently borrowed from Aristotle's "Qua;stiones mecha- nica;". This Aristotelean commentary is mentioned by Roger Bacon in his "Opus majus"; together with an enlarged edition of the "Liber Euclidis de pon- deribus", it was printed at Nuremberg, in 1533, by