What is a “dustof snow”? What does the poet say has changed his mood? How hasthe poet’s mood changed?

A“dust of snow” could mean a freckle of snow or it couldalso refer to the little white flowers thatcan be found on hemlock tree. This “dust of snow” changedthe poet’s mood. The poet’s mood changed from that ofdismay to joy. He was holding the day in regret when this dust ofsnow fell on him and this simple little thing brought him some joy.