Words of the day - Petrichor Geosmin and argillaceous

'Petrichor' drifted through my consciousness early this morning, 4am'ish, from the faint radio - and in my semi-conscious state I thought 'ah, I'll have to look that up when I rise'. The earthy scent of rain on dry soil. It's very apt since the rain has been falling pretty well incessantly here in Eastern Australia for a month or more now. The term was coined in 1964 (previously referred to as as 'argillaceous odour' smelling of clay); geosmin is a compound the scent of which humans are particularly sensitive to. Geosmin is released most readily by light rain, although the rain here has been scarcely been light with the flooding again of Lismore for the second time in a month.