what does the passage:
1 Love is a smoke made with the fume of sighs; 
2 Being purg’d, a fire sparkling in lovers’ eyes; 
3 Being vex’d, a sea nourish’d with loving tears. 
4 What is it else? A madness most discreet, 
5 A choking gall, and a preserving sweet. 
mean in romeo and juliet?