113 
MULTIPLIER—NODAL. 
xi, 495; of extraordinaries, xn, 461—2; complex, in elliptic functions, xn, 556—7; (see also Trans 
formation). 
Multiplier: Jacobi’s theory of, i, 276, 279; theory of, in differential equations, x, 102—6; in elliptic 
integrals, x, 139. 
Multiplier Equations : in elliptic functions, ix, 138—47, xn, 507. 
Murdoch, P.: Newtoni Genesis Curvarum x>er Umbras, v, 284, 288; curve classification, v, 354; cubic 
curves and cones, v, 402; the simplex cubical parabola, vi, 101. 
Murphy, H.: four points in plane or space, vn, 585. 
Murphy, R.: Legendre’s coefficients, i, 376. 
Music and Mathematics: Sylvester on, xm, 45. 
Napier, J.: logarithms, xi, 447. 
Natani, L. : Pfaffian equations, iv, 515. 
Nature: notice on Sylvester, xm, 43—8. 
Neg : the abbreviation in groups, xm, 119. 
Negative : the rule of signs, iv, 595—6, xi, 492. 
Negative Deficiency: vm, 397. 
Neptune : Newcomb’s astronomical work, ix, 180—4. 
Neutral: the term, vi, 101. 
Newcomb, S.: astronomical work of, ix, 176—84. 
Newton, Sir I.: cubic curves, iv, 122; rectilinear motion, iv, 515, 590; central forces, iv, 515, 590; 
parabolas, v, 284; curve classification, v, 354, 364—6, 396—9; diameter, v, 362; cubic curves, 
v, 401, 551, xi, 464; conics, v, 562 ; forms of cubical parabolas, vi, 101; theorem as to roots of 
equations, x, 5; Principia, xi, 447—8; branches of curves, xi, 477; theory of equations, xi, 500, 
502; roots of algebraic equation, xm, 35; Sylvester’s work at rule of, xm, 46; tactions, xm, 
151—69 ; Newton-circle, the term, xm, 152. 
Newton-Fourier Theorem: imaginary roots, x, 405—6, xi, 143, xm, 36; extension to complex variables, 
x, 405—6; theory of equations, xi, 114—21, 122. 
Nexal: the term, vm, 73. 
Nil: the term, xii, 66. 
Nilfactum : and quantic, vi, 466. 
Nilpotent: the term, xn, 61. 
Nilvalent: the word, ix, 202. 
Nine-point Circle: xm, 517—9, 520—l, 548—51. 
Nitrogen: tree of, ix, 430. 
Nivellators : Sylvester’s theory of, xm, 47. 
Nodal: the term, vii, 244. 
Nodal Anallagmatic: the term, vm, 67. 
Nodal Bicircular Quartic: mechanical description, vii, 182—8. 
Nodal Cubic: vi, 171—4, vii, 555. 
Nodal Curves: of developable from quartic, v, 135—7; of cubic surface, vi, 450; centro-surface of 
ellipsoid, vm, 332—52. 
Nodal Director : the term, v, 169—70. 
Nodal Generator of Scrolls: v, 169—70, 179—81. 
Nodal Isochronic: the term, vn, 473. 
Nodal Locus: in singular solutions, vm, 533. 
Nodal Quartic: defined, v, 10; mechanical description of bicircular, vn, 182—8; and hyperelliptie 
functions, xn, 196—208. 
Nodal Quartic Surfaces (see Quartic Surfaces). 
C. XIV. 
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