And weighs and measures all things but himself!"

Irritation is an

Muse,

the torpedo and by the gymnotus, are supposed to be similar to those of the Galvanic pile, as they are produced in water. Which water is decomposed by the Galvanic pile and converted into oxygen and hydrogen gas. See Additional Note XII.

The magnetic ether may also be supposed to consist of two fluids, one of which attracts the needle, and the other repels it; and, perhaps, chemical affinities, and gravitation itself, may consist of two kinds of ether surrounding the particles of bodies, and may thence attract at one distance and repel at another; as appears when two insulated electrised balls are approached to each other, or when two small globules of mercury are pressed together.

sense in consequence of the appulses of external bodies. The word perception includes both the action of the organ of sense in consequence of the impact of external objects and our attention to that action; that is, it expresses both the motion of the organ of sense, or idea, and the pain or pleasure that succeeds or accompanies it. Irritative ideas are those which are preceded by irritation, which is excited by objects external to the organs of sense as the idea of that tree, which either I attend to, or which I shun in walking near it without attention. In the former case it is termed perception, in the latter it is termed simply an irritative idea.

And young Sensation, 1. 72. Sensation is an exertion or change of the central parts of the sensorium or of the whole of it, beginning at some of those extreme parts of it which reside in the muscles or organs of sense. Sensitive ideas are those which are preceded by the sensation of pleasure or pain, are termed Imagination, and constitute our dreams and reveries.

Quick Volition springs, 1. 73. Volition is an exertion or change of the central parts of the sensorium, or of the whole of it terminating in some of those extreme parts of it which reside in the muscles and organs of sense. The vulgar use of the word memory is too unlimited for our purpose: those ideas which we voluntarily recall are here termed ideas of recollection, as when we will to repeat the alphabet backwards. And those ideas which are suggested to us by preceding ideas are here termed ideas of suggestion, as whilst we repeat the alphabet in the usual order; when by habits previously acquired B is

Each passing moment, unobserved restrain
The wild discordancies of Fancy's train;
But leave uncheck'd the Night's ideal streams,
Or, sacred Muses! your meridian dreams.

suggested by A, and C by B, without any effort of deliberation. Reasoning is that operation of the sensorium by which we excite two or many tribes of ideas, and then re-excite the ideas in which they differ or correspond. If we determine this difference, it is called judgment, if we in vain endeavour to determine it, it is called doubting.

If we re-excite the ideas in which they differ, it is called distinguishing. If we re-excite those in which they correspond, it is called comparing. Each passing moment, 1. 81. During our waking hours, we perpetually compare the passing trains of our ideas with the known system of nature, and reject those which are incongruous with it; this is explained in Zoonomia, Sect. XVII. 3. 7. and is there termed Intuitive Analogy. When we sleep, the faculty of volition ceases to act, and in consequence the uncompared trains of ideas become incongruous and form the farrago of our dreams; in which we never experience any surprise, or sense of novelty.

Association steers, 1. 91. Association is an exertion or change of some extreme part of the sensorium residing in the muscles and organs of sense in consequence of some antecedent or attendant fibrous contractions. Associate ideas, therefore, are those which are preceded by other ideas or muscular motions, without the intervention of irritation, sensation, or volition between them; these are also termed ideas of suggestion.

The branching forehead, 1. 103. The peculiarities of the shapes of animals which distinguish them from each other, are enumerated in Zoo

The struggling lamb, and rends with ivory jaws;

110

The tropic eel, electric in his ire,
Alarms the waves with unextinguish'd fire;
The fly of night illumes his airy way,
And seeks with lucid lamp his sleeping prey;
Fierce on his foe the poisoning serpent springs,
And insect armies dart their venom'd stings.

"Proud Man alone in wailing weakness

born,

No horns protect him, and no plumes adorn; No finer powers of nostril, ear, or eye, Teach the young Reasoner to pursue or fly.— Nerved with fine touch above the bestial throngs, 121

The hand, first gift of Heaven! to man belongs; Untipt with claws the circling fingers close, With rival points the bending thumbs oppose, Trace the nice lines of Form with sense refined, And clear ideas charm the thinking mind.

nomia, Sect. XXXIX. 4. 8. on Generation, and are believed to have been gradually formed from similar living fibres, and are varied by reproduction. Many of these parts of animals are there shown to have arisen from their three great desires of lust, hunger, and security.

The tropic eel, 1. 111. Gymnotus electricus. The fly of night, 1. 113. Lampyris noctiluca. Fire-fly.

The hand, first gift of Heaven, 1. 122. The human species in some of their sensations are much inferior to animals, yet the accuracy of the sense of touch, which they possess in so eminent a degree, gives them a great superiority of understanding; as is well observed by the ingenious Mr. Buffon. The extremities of other animals terminate in horns, and hoofs, and claws, very unfit for the sensation of touch; whilst the human hand is finely adapted to encompass its object with this organ of sense, Those animals who have clavicles or collarbones, and thence use their fore-feet like hands, as cats, squirrels, monkeys, are more ingenious than other quadrupeds, except the elephant, who has a fine sense at the extremity of his proboscis; and many insects from the possessing finer organs of touch have greater ingenuity, as spiders, bees, wasps.

Trace the nice lines of form, 1. 125. When the idea of solidity is excited a part of the extensive organ of touch is compressed by some external body, and this part of the sensorium so compressed exactly resembles in figure the figure of the body that compressed it. Hence when we acquire the idea of solidity, we acquire at the same time the idea of figure; and this idea o figure, or motion of a part of the organ of touch exactly resembles in its figure the figure of the body that occasions it; and thus exactly ac quaints us with this property of the external world.

"Slow could the tangent organ wander o'er The rock-built mountain and the winding shore ;

No apt ideas could the pigmy mite,
Or embryon emmet to the touch excite;
But as cach mass the solar ray reflects,

The eye's clear glass the transient beams collects;
Bends to their focal point the rays that swerve,
And paints the living image on the nerve.
So in some village-barn, or festive hall,
The spheric lens illumes the whiten'd wall; 140
O'er the bright field successive figures fleet,
And motley shadows dance along the sheet.→→
Symbol of solid forms is colour'd light,
And the mute lang uage of the touch is sight.

prise

With step retreating, and expanded eyes;

Now, as the whole universe with all its parts possesses a certain forin or figure, if any part of it moves, that form or figure of the whole is varied. Hence, as motion is no other than a perpetual variation of figure, our idea of motion is also a real resemblance of the motion that produced it.

Hence arises the certainty of the mathematical sciences, as they explain these properties of bodies, which are exactly resembled by our ideas of them, whilst we are obliged to collect almost all our other knowledge from experiment; that is, by observing the effects exerted by one body upon another.

The mute language of the touch, 1. 144. Our eyes observe a difference of colour, or of shade, in the prominences and depressions of objects, and that those shades uniformly vary when the sense of touch observes any variation. Hence when the retina becomes stimulated by colours or shades of light in a certain form, as in a circular spot, we know by experience 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.

Starts young Surprise, 1. 145. Surprise is occaBioned by the sudden interruption of the usual

Beauty's fine forms attract our wondering eyes, And soft alarms the pausing heart surprise.

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 must consequently possess trains both of waking and sleeping ideas. Surprise must therefore be strongly excited at its nativity, as those trains of ideas must instantly be dissevered by the sudden and violent sensations occasioned by the dry and cold atmosphere, the hardness of external bodies, light, sound, and odours; which are accompanied with pleasure or pain according to their quantity or intensity.

As some of these sensations become familiar by repetition, other objects not previously attended to present themselves, and produce the idea of novelty, which is a less degree of surprise, and like that is not perceived in our dreams, though for another reason; because in sleep we possess no voluntary power to compare our train of ideas with our previous knowledge of nature, and do not therefore perceive their difference by intuitive analogy from what usually occurs.

As the novelty of our ideas is generally attended with pleasurable sensation, from this arises Curiosity, or a desire of examining a variety of objects, hoping to find novelty, and the pleasure consequent to this degree of surprise. See Additional Note VII. 3.

And meeting lips, 1. 152. Young children put small bodies into their mouths, when they are satiated with food, as well as when they are hungry, not with design to taste them, but use their lips as an organ of touch to distinguish the shape of them. Puppies, whose toes are terminated with nails, and who do not much use their fore feet as hands, seem to have no other means of acquiring a knowledge of the forms of external bodies, and are therefore perpetually playing with things by taking them between their lips.