Sentence:  [...] from the earliest time that he could remember, there had lain pleasantly in the end of his nose the various scents of mint—used to <WSD>freshen</WSD> the water in the ewers—or of basil, camomile, fennel, hysop and lavender—which he had been taught to strew on the rushy floors [...] 
Meaning of the word marked with <WSD> tags:  To remove or cover unpleasant qualities such as staleness, bad odour or taste (in air, breath, water, etc.).