"The number.
"The duration.
"We have just spoken of the color.
"The movement is personified by a series of gestures that people make or by a series of changes to which they subject things.
"The form is represented by the different outlines.
"The number by their quantity.
"The duration by their length; one will judge of the length of time it takes to walk a road by seeing the length of it.
"The act of listening is divided into three degrees.
"First degree, to hear.
"Second degree, to understand.