Milton writes, book i. v. 63—
No light, but rather DARKNESS VISIBLE
Served only to discover sights of woe.
Perhaps borrowed from Spenser:—
A little glooming light, much like a shade.
Faery Queene, b. i. c. 2. st. 14.
This fine expression of "DARKNESS VISIBLE" the Doctor's critical sagacity has thus rendered clearer:—
No light, but rather A TRANSPICIUOUS GLOOM.
Again, our learned critic distinguishes the 74th line of the first book—
As from the centre thrice to the utmost pole,
as "a vicious verse," and therefore with "happy conjecture," and no taste, thrusts in an entire verse of his own composition—
DISTANCE WHICH TO EXPRESS ALL MEASURE FAILS.