Besides thus setting forth those varieties of atoms and atomic motions which produced corresponding varieties of colour, Demokritus also brought to view the intermediate stages whereby they realised the act of vision. All objects, compounds of the atoms, gave out effluvia or images resembling themselves. These effluvia stamped their impression, first upon the intervening air, next upon the eye beyond: which, being covered by a fine membrane, and consisting partly of water, partly of vacuum, was well calculated to admit the image. Such an image, the like of which any one might plainly see by looking into another person's eye, was the immediate cause of vision.[229] The air, however, was no way necessary as an intervening medium, but rather obstructive: the image proceeding from the object would be more clearly impressed upon the eye through a vacuum: if the air did not exist, vision would be so distinct, even at the farthest distance, that an object not larger than an ant might be seen in the heavens.[230] Demokritus believed that the visual image, after having been impressed upon the eye, was distributed or multiplied over the remaining body.[231] In like manner, he believed that, in hearing, the condensed air carrying the sound entered with some violence through the ears, passed through the veins to the brain, and was from thence dispersed over the body.[232] Both sight and hearing were thus not simply acts of the organ of sense, but concurrent operations of the entire frame: over all which (as has been already stated) the mental or vital particles were assumed to be disseminated. [Footnote 229: Theophrast. De Sensu, s. 50. [Greek: to\n a)e/ra to\n metaxu\ tê=s o)/pseôs kai\ tou= o(rôme/nou tupou=sthai], &c. Aristotel. De Sensu, c. 2, p. 438, a. 6. Theophrastus notices this intermediate [Greek: a)potu/pôsis e)n tô=| a)e/ri] as a doctrine peculiar ([Greek: i)di/ôs]) to Demokritus: he himself proceeds to combat it (51, 52).] [Footnote 230: Aristotel. De Animâ, ii. 7-9, p. 419, a. 16.] [Footnote 231: Theophrastus, De Sensu, s. 54.] [Footnote 232: Theophrastus, De Sensu, 55, 56. [Greek: tê\n ga\r phônê\n ei)=nai puknoume/nou tou= a)e/ros kai\ meta\ bi/as ei)sio/ntos], &c. Demokritus thought that air entered into the system not only through the ears, but also through pores in other parts of the body, though so gently as to be imperceptible to our consciousness: the ears afforded a large aperture, and admitted a considerable mass.] [Side-note: Differences of taste--how explained.]