Archive for October 14th, 2021

Herapathite: an example of (double?) serendipity.

Thursday, October 14th, 2021

On October 13, 2021, the historical group of the Royal Society of Chemistry organised a symposium celebrating ~150 years of the history of (molecular) chirality. We met for the first time in person for more than 18 months and were treated to a splendid and diverse program about the subject. The first speaker was Professor John Steeds from Bristol, talking about the early history of light and the discovery of its polarisation. When a slide was shown about herapathite[1] my “antennae” started vibrating. This is a crystalline substance made by combining elemental iodine with quinine in acidic conditions and was first discovered by William Herapath as long ago as 1852[2] in unusual circumstances. Now to the serendipity!



  1. B. Kahr, J. Freudenthal, S. Phillips, and W. Kaminsky, "Herapathite", Science, vol. 324, pp. 1407-1407, 2009.
  2. W.B. Herapath, "XXVI. On the optical properties of a newly-discovered salt of quinine, which crystalline substance possesses the power of polarizing a ray of light, like tourmaline, and at certain angles of rotation of depolarizing it, like selenite", The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, vol. 3, pp. 161-173, 1852.