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Monday, April 28, 2008

petrichor


It rained yesterday; not once but several times. As I sat on the front porch watching the first shower pass, two towhees, a robin and a wood thrush scurried about in the leaves. They were enjoying the rain as much as I.

The smell was glorious, or should I say the petrichor.

In 1964, two Australian researchers coined the term “petrichor” for an article they were writing for the journal “Nature.” The word comes from the Greek petros (stone) + ichor (the fluid that is supposed to flow in the veins of the gods in Greek mythology). They defined petrichor (pronounced PET-ri-kuhr) as the pleasant smell that accompanies the first rain after a dry spell.

Wiki states: “In the article, the authors describe how the smell derives from an oil exuded by certain plants during dry periods, whereupon it is adsorbed by clay-based soils and rocks. During rain, the oil is released into the air along with another compound, geosmin, producing the distinctive scent. In a follow-up paper, Bear and Thomas (1965) showed that the oil retards seed germination and early plant growth.”

If the oil is present in the soil, seeds will not sprout because conditions are too dry to support young life.

Nature's processes never cease to amaze.

Petrichor is generally described as pleasant and refreshing and is one of the most frequently cited "favorite smells.” As indeed it is.

- Thanks Kimberly!!

2 comments:

  1. That is so interesting! I love that smell.

    Now I can amaze and astound my friends next time it rains.

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  2. Yes britecloud.

    It's a wonderful smell. Now we know it has a name and what causes it.

    I was unaware of the term. My friend Kimberly shared it with me.

    ReplyDelete