On Dreams   

seen moving: persons become very deaf after hearing loud noises, and

after smelling very strong odours their power of smelling is impaired;

and similarly in other cases. These phenomena manifestly take place in

the way above described.

That the sensory organs are acutely sensitive to even a slight

qualitative difference [in their objects] is shown by what happens

in the case of mirrors; a subject to which, even taking it

independently, one might devote close consideration and inquiry. At

the same time it becomes plain from them that as the eye [in seeing]

is affected [by the object seen], so also it produces a certain effect

upon it. If a woman chances during her menstrual period to look into a

highly polished mirror, the surface of it will grow cloudy with a

blood-coloured haze. It is very hard to remove this stain from a new

mirror, but easier to remove from an older mirror. As we have said

before, the cause of this lies in the fact that in the act of sight

there occurs not only a passion in the sense organ acted on by the

polished surface, but the organ, as an agent, also produces an action,

as is proper to a brilliant object. For sight is the property of an

organ possessing brilliance and colour. The eyes, therefore, have

their proper action as have other parts of the body. Because it is

natural to the eye to be filled with blood-vessels, a woman's eyes,

during the period of menstrual flux and inflammation, will undergo a

change, although her husband will not note this since his seed is of

the same nature as that of his wife. The surrounding atmosphere,

through which operates the action of sight, and which surrounds the

mirror also, will undergo a change of the same sort that occurred

shortly before in the woman's eyes, and hence the surface of the

mirror is likewise affected. And as in the case of a garment, the

cleaner it is the more quickly it is soiled, so the same holds true in

the case of the mirror. For anything that is clean will show quite

clearly a stain that it chances to receive, and the cleanest object

shows up even the slightest stain. A bronze mirror, because of its