That evening I was making dinner, and measured out a quarter cup of oil, a bit more than 50 mL. I set it down on the counter for a moment, and then knocked it over with my hand. Oil was suddenly everywhere. It flowed over the counter top, onto the drawers below. Onto the floor. It was everywhere. I couldn’t believe how such a small amount could spread so far.
At one level, I do understand why oil makes such a mess when it spills. It has a low surface tension (about 30 dynes/cm — and yes, I looked it up, see Albert Halpern, J. Phys. Chem. 1949, 53, 6, 895–897), about half that of water. A teaspoon of oil can spread out to cover about 22 thousand square feet of water. I had spilled ten times that, no wonder it was everywhere in my 200 square foot kitchen.
The messiah, the anointed one. All these years as a chemist, all the psalms I’ve prayed and I’d never really thought, “Why oil?” Oil burns, giving light. It binds, turning flour into bread. It soothes, it’s a balm. It doesn’t evaporate, rather it protects what it covers. It eases friction. Oil is costly. So was the grace that flowed from Calvary. And oil spreads out and out, reminding me that the mercy of God knows no bounds.
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Benjamin Franklin famously measured the spread of oil on water in a London pond. And in looking through the literature about surface tension of plant oils discovered that you can extract oil from carrots. And that what you get is comparable to olive oil in many of its physical properties.
Illustration is Raphael’s fresco of the anointing of David by Samuel, part of a series in the loggia of the Apostolic Palace in Vatican City. I walked through there in June of 2016, but will admit both have been agape at the frescos and not having noticed this one in particular.
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