The Bracelet to Julia

Why I tie about thy wrist,
Julia, this silken twist;
For what other reason 'tis
But to show thee how, in part,
Thou my pretty captive art?
But thy bond slave is my heart:
'tis but silk that bindeth thee,
Knap the thread and thou art free;
But 'tis otherwise with me:
-I am bound and fast bound, so
That from thee I cannot go;
If I could, I would not so.