xperience that this is a sign that
a tangible body is before us; and that its figure is
resembled by the miniature figure of the part of the organ of
vision that is thus stimulated.

Here whilst the stimulated part of the retina resembles
exactly the visible figure of the whole in miniature, the
various kinds of stimuli from different colours mark the
visible figures of the minuter parts; and by habit we
instantly recall the tangible figures.

So that though our visible ideas resemble in miniature the
outline of the figure of coloured bodies, in other respects
they serve only as a language, which by acquired associations
introduce the tangible ideas of bodies. Hence it is, that
this sense is so readily deceived by the art of the painter
to our amusement and instruction. The reader will find much
very curious knowledge on this subject in Bishop Berkeley's
Essay on Vision, a work of great ingenuity.]

"HENCE in Life's portico starts young Surprise
With step retreating, and expanded eyes;
The virgin, Novelty, whose radiant train
Soars o'er the clouds, or sinks beneath the main,
With sweetly-mutable seductive charms
Thrills the young sense, the tender heart alarms. 150
Then Curiosity with tracing hands
And meeting lips the lines of form demands,
Buoy'd on light step, o'er ocean, earth, and sky,
Rolls the bright mirror of her restless eye.
While in wild groups tumultuous Passions stand,
And Lust and Hunger head the Motley band;
Then Love and Rage succeed, and Hope and Fear;
And nameless Vices close the gloomy rear;
Or young Philanthropy with voice divine
Convokes the adoring Youth to Virtue's shrine; 160
Who with raised eye and pointing finger leads
To truths celestial, and immortal deeds.

[Footnote: _Starts young Surprise_, l. 145. Surprise is
occasioned by the sudden interruption of the usual trains of
our ideas by any violent stimulus from external objects, as
from the unexpected discharge of a pistol, and hence does not
exist in our dreams, because our external senses are closed
or inirritable. The fetus in the womb must experience many
sensations, as of resistance, figure, fluidity, warmth,
motion, rest, exertion, taste; and mus