Here is another distinctly unfriendly-looking molecule, arsphenamine. For 30-40 brutish years, this was our single best treatment for syphilis. We owe this distinct pleasure to Paul Ehrlich, father of chemotherapy (coined the term, along with “Magic Bullet.”) In the early 20th century, he was working on histology, or staining cells. He reasoned that if we had compounds that stained only certain types of cells, maybe we could find one that would kill certain cells. Like syphilis spirochetes.

While this was a primitive theory of selectivity, Elrich used it to good effect, and six hundred five dead ends later, he released arsphenamine upon the world:

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Mercury is a weird one. It’s quite toxic, and you’ll do well not to handle it casually, but as the metal it’s actually not that bad. If a thermometer breaks, you can probably clean up the area as best you can, then sprinkle zinc dust or sulfur (disputed, see here) on it to keep it from evaporating. If you spill it in, say, an oven, like in the lab, or spill a great deal, it can be a bigger problem - some labs have mercury bubblers with literally pounds of the stuff in them - for most applications, you can use mineral oil, but especially in academic labs, you see a lot of mercury still floating around.

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Molecule of the Day will not be seen as scheduled this Saturday, May 6th due to the author’s heartbreaking failure to synthesize soap scum from bar soap and epsom salts, leaving me with nothing to report today. (Nice way to kill an hour and dirty up your kitchen, though). Plus, I have a pound (454g) of epsom salts. What do I do with this? Wait until I’m 80, then take baths in it?

On a sadder note, two days ago was the anniversary of the Kent State Shootings (Wikipedia, Google News), and 8-9 days from now is the anniversary of the Jackson State Shootings (Wikipedia, Google News - not much there for another week or so, of course). We hear less and less about these every year.

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So, yesterday was Sodium Dodecyl Sulfate, or SDS. Today is the carboxylic acid analogue, or lauric acid. This is just a twelve-carbon, aliphatic, unsaturated carboxylic acid. One big difference between it and SDS is that it can form an insoluble complex with divalent metal ions like magnesium and calcium. This is, of course, soap scum. Follow that link! If you are one of those unfortunate souls who has soft water, you can make your own soap scum at home.

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Corundum is a funny one. It is aluminum (III) oxide, or Al₂O₃. This means that it is composed of aluminum atoms, three electrons shy of the zero oxidation state (the shiny, silvery, regular metal). You could also call this an Al³⁺ compound, instead of an aluminum (III) compound. The charge is balanced by the oxygen (-2) atoms. In a crystal, it looks like this:

The funny thing about corundum is, when you have it in a clean single crystal, you get something much different. You know them as sapphires…

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