These follies are within you and shine through you like the water in an urinal

From Two Gentlemen of Verona (2.1):

VALENTINE
Why, how know you that I am in love?
SPEED
Marry, by these special marks: first, you have
learned, like Sir Proteus, to wreathe your arms,
like a malecontent; to relish a love-song, like a
robin-redbreast; to walk alone, like one that had
the pestilence; to sigh, like a school-boy that had
lost his A B C; to weep, like a young wench that had
buried her grandam; to fast, like one that takes
diet; to watch like one that fears robbing; to
speak puling, like a beggar at Hallowmas. You were
wont, when you laughed, to crow like a cock; when you
walked, to walk like one of the lions; when you
fasted, it was presently after dinner; when you
looked sadly, it was for want of money: and now you
are metamorphosed with a mistress, that, when I look
on you, I can hardly think you my master.
VALENTINE
Are all these things perceived in me?
SPEED
They are all perceived without ye.
VALENTINE
Without me? they cannot.
SPEED
Without you? nay, that’s certain, for, without you
were so simple, none else would: but you are so
without these follies, that these follies are within
you and shine through you like the water in an
urinal, that not an eye that sees you but is a
physician to comment on your malady.

A urinal at this time was a glass vessel used by a doctor for storing and examining a patient’s urine.