ey discovered
some of its most important reagents--sulphuric acid, nitric acid,
alcohol. They applied that science in the practice of medicine, being
the first to publish pharmacopoeias or dispensatories, and to include in
them mineral preparations. In mechanics, they had determined the laws
of falling bodies, had ideas, by no means indistinct, of the nature of
gravity; they were familiar with the theory of the mechanical powers. In
hydrostatics they constructed the first tables of the specific gravities
of bodies, and wrote treatises on the flotation and sinking of bodies
in water. In optics, they corrected the Greek misconception, that a
ray proceeds from the eye, and touches the object seen, introducing
the hypothesis that the ray passes from the object to the eye. They
understood the phenomena of the reflection and refraction of light.
Alhazen made the great discovery of the curvilinear path of a ray of
light through the atmosphere, and proved that we see the sun and moon
before they have risen, and after they have set.

AGRICULTURE AND MANUFACTURE. The effects of this scientific activity are
plainly perceived in the great improvements that took place in many
of the industrial arts. Agriculture shows it in better methods of
irrigation, the skillful employment of manures, the raising of improved
breeds of cattle, the enactment of wise codes of rural laws, the
introduction of the culture of rice, and that of sugar and coffee. The
manufactures show it in the great extension of the industries of silk,
cotton, wool; in the fabrication of cordova and morocco leather, and
paper; in mining, casting, and various metallurgic operations; in the
making of Toledo blades.

Passionate lovers of poetry and music, they dedicated much of their
leisure time to those elegant pursuits. They taught Europe the game of
chess; they gave it its taste for works of fiction--romances and novels.
In the graver domains of literature they took delight: they had many
admirable compositions on such subjects as the instability of human
greatness; the consequences of irreligion; the reverses of fortune; the
origin, duration, and end of the world. Sometimes, not without surprise,
we meet with ideas which we flatter ourselves have originated in our
own times. Thus our modern doctrines of evolution and development were
taught in their schools. In fact, they carried them much farther than we
are disposed to do, extending them even to inorganic or mineral