An evocative olfactory metaphor for the effect of a tangle of emotions on a young man’s heart.  Elsewhere, Joyce uses another metaphor with plant fragrances to describe the impact of poems. 

Pride and hope and desire like crushed herbs in his heart sent up vapours of maddening incense before the eyes of his mind. 

Source: James Joyce, A Portrait of the Artist as a Young Man (Harmondsworth: Penguin, 1964), p. 86

Photo credit: gate74 at pixabay