CLASSIFICATION. 
Geometry 
The Node-cusp, 343 ; Higher Singulaiities of Plane Curves, 354, 374 
Curves in space (as defined by Cone and Monoid Surface), 302, 305 
Correspondence of Points on Plane Curve, 377 
Sextactic Points of Plane Curve, 341 
Lines in Involution, 300 ; Involution, 348, 349 
Elimination and Theory of Curves, 338, 352 
Conics touching given Curves, 306 
Conics, 325, 331, 342, 355, 371, 380 ; Spherical, 327 
Cubic Curves and Cones, 345, 350, 351 
Cubic Surfaces 322, 328, 333 
Quadric Cones and Surfaces, 301, 314, 332, 366 
Quartic Curves, 361, 367 
Quartic Surfaces, 313, 360 ; Steiner’s, 353 ; 16-nodal, 356 
Caustics, 359 
Equilibrium of Four Forces, 376 
Evolutes, 363 
In-and-circumscribed Polygon, 303 
Surfaces, 324; Developable, 344, 372, 373; Skew, 339, 340 
Miscellaneous, 315, 325, 364, 365, 368, 370, 382; and 383, (see contents, p. 612) 
Polyhedra, Notes on, 375: the л-faced polyacra, 308 
Lobatschewsky’s Imaginary Geometry, 362 
Partitions of Close, 312 
Pedal Curves, 329 
Umbilici, 330 
Analysis 
Algebra, the Notion and Boundaries of, 347 
Differential Equations, 317 ; theorem of Jacobi’s, 304; for Umbilici, 330 
Determinants, 309 ; Commutants, 369 
Binary Quadratic Forms (numerical), tables of, 335 
Binary Forms, 326, 346 
Roots of quadratic equation, 337 
Elimination, 336, 338, 352, 381