902 
INDEX. 
Bunsen (Professor R.) and Roscoe (Dr. H. E.). Part 11. Phenomena of Photo-ehemical Induction, 
381. — Influence of the intensity of the light, and progress of the induction, 386; subsidence 
of the induced condition on cutting off the light, 387 ; influence of foreign gases, 389 ; induction 
not referable to an allotropic modification of either gas, 397; explanation of the phenomenon attri- 
buted by M. Becquerel to “ continuing rays,^^ 400. 
Part III. Optical and Chemical Extinction of 
the Chemical Rays, 601. — Consumption of rays in producing photo-chemical change, 616. 
Butyle, obtained from Boghead coal, 453. 
C. 
Cahours (M. a.) and Hofmann (Dr. A. W.). Researches on a New Class of Alcohols, 555 (see Hof- 
mann). 
Researches on the Phosphorus-Bases, 575 (see Hofmann). 
Caproyle, obtained from Boghead coal, 457. 
Caproylene, obtained from Boghead coal, 743. 
Caustics, a memoir upon, 373 (see Cayley). 
Cayley (Arthur, Esq.). A Memoir upon Caustics, 373. — General formulae, 373 ; secondary caustic, 
375 ; rays proceeding from a point, caustic by refraction at a line, 377 ; investigation relative to 
successive reflexions at a circle, 379 ; caustic when the radiant point is at infinity or in the circum- 
ference, 380; rays from a point, caustic by reflexion at a circle, 387 ; by refraction at a circle, 397 ; 
a seeondary caustic is the oval of Descartes, or Cartesian, 398 ; the same caustic produced by six 
systems of a radiant point and refracting circle, 399 ; case in which the Cartesian moves off" to 
infinity, 310. 
On Curves of the Third Order, 415. — Definitions, See., 415 ; group of theo- 
rems relating to the conjugate pole of a cubic, 416; analytical investigations, &c., 418; theorem 
relating to a curve of the third class, 438 ; geometi-ical definition of the Quippian, 438 ; theorem 
relating to a line which meets thi-ee given conics in six points in involution, 439 ; completion of 
the theory in Liouville, and comparison with analogous theorems of Hesse, 431 ; various investi- 
gations and theorems, 433 ; formulae for the intersection of a cubic curve and a line, 435 ; formulae 
for the satellite line and point, 436 ; theorems relating to the satellite point, 439 ; investigations 
and theorems relating to the first or conic polar of a point of the cubic, 443 ; recapitulation of 
geometrical definitions of the Pippian, 445. 
A Memoir on the Symmetric Functions of the Roots of an Equation, 489. — 
Tables, 494. 
Memoir on the Resultant of a System of two Equations, 703. 
On the Symmetric Functions of the Roots of certain Systems of two Equa- 
tions, 717. 
A Memoir on the Conditions for the Existence of given Systems of Equalities 
among the Roots of an Equation, 737. 
Tables of the Sturmian Functions for Equations of the Second, Thii'd, Fourth 
and Fifth Degrees, 733. 
Comparison of transcendents, 745. 
Conductive powers of various substances, experimental researches on the, 805 (see Hopkins). 
CuRREY (Frederick, Esq.). On the Fruetification of certain Sphseriaceous Fungi, 543. 
