As a rule, he whom you wish to represent talking to many people will consider the subject of which he has to treat, and will fit his gestures to this subject--that is to say, if the subject is persuasion, the gestures should serve this intention; if the subject is explanation by various reasons, he who speaks should take a finger of his left hand between two fingers of his right, keeping the two smaller ones pressed together; his face should be animated and turned towards the people, his mouth slightly opened, so that he seems to be talking. And if he is seated, let him seem to be in the act of slightly raising himself, with his head forward; and if he is standing, make him lean forward a little, with his head towards the people, whom you should represent silent and attentive, all watching, with gestures of admiration, the orator's face. Some old men should have their mouths drawn down at the corners in astonishment at what they hear, drawing back the cheeks in many furrows, and raising their eyebrows where they meet, so as to produce many wrinkles on their foreheads. Some who are seated should hold their tired knees between the interlaced fingers of their hands, and others should cross one knee over the other, and place upon it one hand, so that its hollow supports the other elbow, whose hand again supports the bearded chin. Whatever is wholly deprived of light is complete darkness. Night being in this condition, if you wish to represent a scene therein, you must contrive to have a great fire in this night, and everything that is in closer proximity to this fire will assume more of its colour, because the nearer a thing is to another object, the more it partakes of its nature. And since you will make the fire incline towards a red colour, you will have to give a reddish tinge to all things lighted by it, and those which are farther away from the fire will have to hold more of the black colour of night. The figures which are between you and the fire appear dark against the brightness of the flame, for that part of the object which you perceive is coloured by the darkness of night, and not by the brightness of the fire; and those which flank the fire will be half dark and half reddish. Those which are behind the flames will be altogether illuminated by a reddish light against the black background.