the sound of laughter is as distinct and peculiar as the signs in the face.

Defining laughter according to the anatomy, it is a certain influence of the respiratory nerve of the face, which produces relaxation of the orbicular muscle of the lip, whilst it excites the class of ringentes, and the orbicular muscles of the eyelids into action. In what then does it differ from its opposite, the expression of pain or crying?

I have thrown the expression of weeping, from pain, into the face of a fawn: for there is in weeping something inexpressibly mean and ludicrous when it appears in the countenance of a man.

In the violence of weeping, accompanied with lamentation and outcry, the face is flushed, or rather, I may say, suffused with stagnant blood, and the veins of the forehead are distended. In this we see that the emotion from the beginning affects the muscles of respiration, and confines the motion of the lungs, and that the return of the blood from the head is somewhat impeded. The muscles of the cheeks are in action, as in the former instances; but the influence is now more general. Those which depress the lips and angle of the mouth partake of equal if not more powerful excitement with the ringentes, and the orbicularis muscle of the mouth is not relaxed but drawn open by the prevailing action of its opponents. There is a convulsive action in the muscles about the eyes; the brow is drawn down; the eyes compressed by the eyelids; the cheek raised; the nostril drawn out, and the mouth stretched laterally.

In weeping also, unless the convulsive action of the muscles be very strong, the general expression of grief affects that part of the eyebrows which is next the nose. It is turned up with a peevish expression, and this will correspond with the depression of the corners of the mouth.

In the former edition of this essay I said, if ever we should possess a perfect knowledge of the nerves, it would enable us to comprehend the meaning of that pungent sensation in the nose that precedes the flow of tears, and which is so distinctly described by Homer as influencing Ulysses when he sees his father pour the dust upon his reverend head. The translators do not seem to have understood the truth and full effect of the picture. Odyss. B. 24. Now we know that a branch of the respiratory system of nerves can be traced into the nose: it is this nerve which, being irritated, causes sneezing, which is a convulsion of the respiratory muscles, so directed in their actions as to rid the membrane of the offending body by directing the stream and volume of air by the nostrils instead of the mouth. It is the same nerve, which, feeling the impression in weeping (an impression from a condition of the mind), contracts the motions of the muscles of the face into the expression of weeping; and which, if it prevail powerfully, will at length draw the whole respiratory apparatus of the chest, neck, and face into convulsions.

It will be observed that in laughter, as in crying, in the two extremes of character, the whole apparatus of respiration is early and remarkably affected; a further proof, if any is wanting, of what is delivered in the former essay.

In the next place it is evident, that no theory of tension or relaxation of the muscles generally will explain the effects of either

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of these extreme emotions on the face. There is an action of certain muscles both in laughter and in weeping. Nor can we account for actions so peculiar and so distinctly marked, by supposing them concomitant or accidental to certain voluntary motions which the passion suggests.

The depressing of the angle of the mouth gives an air of despondence and languor to the countenance when accompanied with

a general relaxation of the features, or, in other words, of the muscles. When the corrugator which knits the brows co-operates with it, there is mingled in the expression something of mental energy of moroseness or pain. If the frontal muscle joins its operation, an acute turn upwards is given to the inner part of the eyebrow, very different from the effect of the general action of the frontal muscle, and decidedly characteristic of an aguish debilitating pain, or of discontent, according to the prevailing cast of the rest of the countenance.

But a very limited observation will teach us, that while languor and despondency are indicated by depression of the angle of the mouth, the depression must be slight, not violent: for the DEPRESSOR ANGULI ORIS (N.) cannot act strongly without the combination of a muscle, viz. the sUPERBUS, which quickly produces a revolution in the expression, and makes the nether lip pout contemptuously.

In sorrow general languor pervades the whole countenance. The violence and tension of grief, the agitations, the restlessness, the lamentations, and the tumult, have, like all strong excitements, gradually exhausted the frame. Sadness and regret, with depression of spirits and fond recollections, have succeeded; and lassitude of the whole body, with dejection of face and heaviness of the eyes, are the most striking characteristics. The lips are relaxed and the lower jaw drops; the upper eyelid falls down and