Anyone who's read some of the older chemical literature (or even recent papers by old school chemists) has probably noticed the 'black dot' notation used to depict stereochemistry at ring junctions, particularly by chemists in the US and Canada. Here's a recent example, so you'll know what I'm on about if you don't already.
I don't know how things are in the US, but at no point during my chemical education do I ever remember having this notation explained to me. I recall encountering it for the first time at the start of my PhD, asking around a bit, and then just working it out for myself. Turns out it's actually really simple - a black dot at a ring junction just means that the hydrogen there is on the β-face, i.e. above the plane of the paper. To this day I've never seen this explained in a textbook, and have wondered from time to time where the heck it came from. As named reactions become canonised, the references the seminal papers slowly disappear, and clearly the same thing has happened here, as with many other conventions and nomenclatures. However, not having a name for this notation I'd never been able to trace where it started. Until now.
I recently saw that R. B. Woodward, in his full paper on the synthesis of quinine, gave Harvard colleague R. P. Linstead credit as the creator of this convention, but as our library didn't have the 1937 Chemistry and Industry paper referenced I gave up. However, I saw today another Linstead paper published two years later on the stereochemistry of the hydrogenation of phenanthrene which explains all:
From J. Chem. Soc., 1939, 842.
Strangely, googling 'Linstead notation' and variants thereof doesn't seem to turn up many chemical hits - unfortunately it seems that Linstead didn't get the recognition he deserved. Is anyone aware of this being taught to undergrads or postgrads, or is it something we just have to work out?
1. This essay on the vinylcyclopropane - cyclopentene rearrangement by Tomas Hudlicky is actually quite interesting. You can read it for free here (kindly hosted on the group website).
2. Sir Reginald Patrick Linstead CBE, DSc, HonDSc, DIC, HonFCGI, HonMIMM, FRS (!), was a British chemist and a professor at Harvard with Woodward from 1939.