144 



A HISTORY OF 



However, that it moves in man, a very easy 

 experiment will suffice to convince us. If we 

 keep the head fixed, with any thing between 

 our teeth, the edge of a table for instance, 

 and then open our mouths, we shall find that 

 both jaws recede from it at the same time; 

 the upper jaw rises, the lower falls, and the 

 table remains untouched between them. The 

 upper jaw has motion as well as the under; 

 and, what is remarkable, it has its proper 

 muscles behind the head for thus raising and 

 depressing it. Whenever, therefore, we eat, 

 both jaws move at the same time, though very 

 unequally; for the whole head moving with 

 the upper jaw, of which it makes a part, its 

 motions are thus less observable." In the hu- 

 man embryo, the under jaw is very much ad- 

 vanced before the upper. " In the adult, it 

 hangs a good deal more backward ; and those 

 whose upper and under row of teeth are equal- 

 ly prominent, and strike directly against each 

 other, are what the painters call under-hung ; 

 and they consider this as a great defect in 

 beauty." The under jaw in a Chinese face 

 falls greatly more backward than with us ; 

 and, I am told, the difference is half an inch, 

 when the mouth is shut naturally." In instan- 

 ces of the most violent passion, the under jaw 

 has often an involuntary quivering motion ; 

 and often, also, a state of languor produces 

 another, which is that of yawning. "Every 

 one knows how very sympathetic this kind 

 of languid motion is ; and that for one person 

 to yawn, is sufficient to set all the rest of the 

 company a yawning. A ridiculous instance 

 of this was commonly practised upon the fa- 

 mous M'Laurin, one of the professors at Edin- 

 burgh. He was very subject to have his jaw 

 dislocated; so that when he opened his mouth 

 wider than ordinary, or when he yawned, he 

 could not shut it again. In the midst of his 

 harangues, therefore, if any of his pupils be- 

 gan to be tired of his lecture, he had only to 

 gape or yawn, and the professor instantly 

 caught the sympathetic affection ; so that he 

 thus continued to stand speechless, with his 

 mouth wide open, till his servant, from the 

 next room, was called in to set his jaw again."" 

 When the mind reflects with regret upon 



a Mr. Buffon says, that both jaws, in a perfect face, 

 should be on a level : but this is denied by the best 

 painters. 



some good unattained or lost, it feels an inter- 

 nal emotion, which acting upon the diaphragm, 

 and that upon the lungs, produces a sigh; 

 this, when the mind is strongly affected, is re- 

 peated ; sorrow succeeds these first emotions, 

 and tears are often seen to follow : sobbing is 

 the sigh still more invigorated ; and lamen- 

 tation, or crying, proceeds from the con- 

 tinuance of the plaintive tone of the voice, 

 which seems to implore pity. " There is yet 

 a silent agony, in which the mind appears to 

 disdain all external help, and broods over its 

 distresses with gloomy reserve. This is the 

 most dangerous state of mind : accidents or 

 friendship may lessen the louder kindsof grief; 

 but all remedies for this must be had from 

 within ; and there despair too often finds the 

 most deadly enemy." 



Laughter is a sound of the voice, interrupt- 

 ed and pursued for some continuance. The 

 muscles of the belly, and the diaphragm, are 

 employed in the slightest exertions ; but those 

 of the ribs are strongly agitated in the louder; 

 and the head sometimes is thrown backward, 

 in order to raise them with greater ease. 

 The smile is often an indication of kindness 

 and good-will : it is also often used as a mark 

 of contempt and ridicule. 



Blushing proceeds from different passions ; 

 being produced by shame, anger, pride, and 

 joy. Paleness is often also the effect of an- 

 ger ; and almost ever attendant on fright and 

 fear. These alterations in the colour of the 

 countenance are entirely involuntary; all the 

 other expressions of the passions are, in some 

 small degree, under control; but blushing and 

 paleness betray our secret purposes ; and we 

 might as well attempt to stop them, as the 

 circulation of the blood, by which they are 

 caused. 



The whole head, as well as the features of 

 the face, takes peculiar attitudes from its pas 

 sions : it bends forward, to express humility, 

 shame, or sorrow; it is turned to one side in 

 languor or in pity; it is thrown with the chin 

 forward in arrogance and pride; erect in 

 self-conceit and obstinacy ; it is thrown back- 

 wards in astonishment ; and combines its mo- 

 tion to the one side and the other, to express 



[ b Since the publication of this work, the editor has been 

 credibly informed, that the professor had not the defect 

 here mentioned.] 



