of those images which are presented to our eyes in mirrors.

empedocles says that these images are caused by certain effluxes which, meeting together and resting upon the superficies of the mirror, are perfected by that fiery element emitted by the said mirror, which transforms withal the air that surrounds it. democritus and epicurus, that the specular appearances are made by the subsistence of the images which flow from our eyes; these fall upon the mirror and remain, while the light returns to the eye. the followers of pythagoras explain it by the reflection of the sight; for our sight being extended (as it were) to the brass, and meeting with the smooth dense surface thereof it is forced back, and caused to return upon itself: the same takes place in the hand, when it is stretched out and then brought back again to the shoulder. any one may use these instances to explain the manner of seeing.