What smelled like perfume to Montag?

The air smelled like perfume.

The air seemed charged with a special calm as if someone had waited there, quietly, and only a moment before he came, simply turned to a shadow and let him through. Perhaps his nose detected a faint perfume, perhaps the skin on the backs of his hands, on his face, felt the temperature rise at this one spot where a person's standing might raise the immediate atmosphere ten degrees for an instant.