INTRODUCTORY
USES OF EXPERIMENT
EARLY SCIENTIFIC NOTIONS
SCIENCES OF OBSERVATION
KNOWLEDGE OF THE ANCIENTS REGARDING LIGHT
DEFECTS OF THE EYE
OUR INSTRUMENTS
RECTILINEAL PROPAGATION OF LIGHT
LAW OF INCIDENCE AND REFLECTION
STERILITY OF THE MIDDLE AGES
REFRACTION
DISCOVERY OF SNELL
PARTIAL AND TOTAL REFLECTION
VELOCITY OF LIGHT
ROEMER, BRADLEY, FOUCAULT, AND FIZEAU
PRINCIPLE OF LEAST ACTION
DESCARTES AND THE RAINBOW
NEWTON'S EXPERIMENTS ON THE COMPOSITION OF SOLAR LIGHT
HIS MISTAKE AS REGARDS ACHROMATISM
SYNTHESIS OF WHITE LIGHT
YELLOW AND BLUE LIGHTS PRODUCE WHITE BY THEIR MIXTURE
COLOURS OF NATURAL BODIES
ABSORPTION
MIXTURE OF PIGMENTS CONTRASTED WITH MIXTURE OF LIGHTS.


§ 1. _Introduction_.

Some twelve years ago I published, in England, a little book entitled
the 'Glaciers of the Alps,' and, a couple of years subsequently, a