If the smell of an herb rubbed onto one's hands, or is just in the air, may one make a bracha on it?
Thank You.
Answer:
One does not recite a bracha on a smell that does not emanate from its original source. This is called "rei'ach she-ein lo ikar" (see Shulchan Aruch 216:7).
Therefore, one does not make a bracha upon smelling one's hands, even if a fragrant herb was rubbed onto them.
All scents are "in the air," and the principle is that one recites a bracha if the smell has a fragrant source that is present.
Best wishes.