Definition (222. 223).--An illustration by experiment (224).--A
guiding rule (225).---An experiment (226).--On indistinctness at
short distances (227--231).--On indistinctness at great distances
(232--234).--The importance of light and shade in the Prospettiva
de' perdimenti (235--239).--The effect of light or dark backgrounds
on the apparent size of objects (240--250).--Propositions on
Prospettiva de' perdimenti from MS. C. (250--262).