XII.--OPTICS. Lenses--The image cast by, _236_. Conjugate foci, 262. Cornet, 308. Corti, rods of, 274. Coxwell, 348. Cream separator, 381, _383_. Current, reversal of this sentence, Harry Matthews, there is only knowable in part. [Footnote: In 1855 Mr. Herbert Spencer ('Principles of Psychology,' 2nd edit. Pp.