INDEX 
TO THE 
PHILOSOPHICAL TRANSACTIONS 
FOR THE YEAR 1868. 
A. 
Airy (G. B.). Computation of the Lengths of the Waves of Light corresponding to the Lines in the 
Dispersion Spectrum measured by Kirchhoff, 29. 
Comparison of Magnetic Disturbances recorded by the Self-registering Magnetometers 
at the Royal Observatory, Greenwich, with Magnetic Disturbances deduced from the corresponding 
Terrestrial Galvanic Currents recorded by the Self-registering Galvanometers of the Royal Obser- 
vatory, 465. 
B. 
Bakerian Lecture. Researches on Vanadium, 1. 
Balanoptera rostrata, anatomy of, 201 (see Carte). 
Bashforth (F.). On the Resistance of the Air to the Motion of Elongated Projectiles having variously 
formed Heads, 417. 
Blood, researches on the, 589 (see Gamgee). 
Bombay, tides of, 685. 
Brain, intimate structure of, 263 (see Clarke). 
Brain, weight of, in different races of man, 505. 
C. 
Carte (A.) and Macalister (A.). On the Anatomy of Balcenoptera rostrata, 201. — Explanation of 
plates, 258. 
Cayley (A.). On the Curves which satisfy given Conditions, 75. 
Second Memoir on the Curves which satisfy given Conditions ; the Principle of Corre- 
spondence, 145. 
Addition to Memoir on the Resultant of a System of two Equations, 173. 
On the Conditions for the existence of Three Equal Roots, or of Two Pairs of Equal 
Roots, of a Binary Quartic or Quintic, 577. 
