Paragraph

 1 2|         darkness is produced.~This theory, however, solves one question
 2 2|           it, the eye must on this theory see itself. But then why
 3 2|          to him to ask why, if his theory be true, the eye alone sees,
 4 3| determinate ratio. To [introduce a theory of colour which would set
 5 3|        visible, this superposition theory, too [i.e. as well as No.
 6 3|       infra], might pass as a real theory of colour-mixture. Indeed,
 7 5|           inclined to rush to this theory of Odour.] Heraclitus implied
 8 5|       smell.~Again, the exhalation theory of odour is analogous to
 9 5|          odour is analogous to the theory of emanations. If, therefore,
10 5|     odorous as having species.~The theory held by certain of the Pythagoreans,
11 7|          it will be found [on this theory of vacant times and imperceptible