l-Physostigmine (Eserine)

In his report (Christison 1855) to the Royal Society of Edinburgh on 5th February 1855 of his pioneering studies upon the toxicology of the Calabar bean by self-experimentation, Robert Christison (see footnote 14 in Chap. 1 ) stated “that its active properties may be concentrated in an alcoholic extract, which constitutes 2.7 per-cent of the seed”. Although experimental details are not presented (Christison 1855), this deficiency was rectified some 8 years later by Thomas Fraser (see footnote 17 in Chap. 1 ), formerly Christison’s assistant at the University of Edinburgh (see footnote 14 in Chap. 1 ), who published the following method for the preparation of the tincture that he used in connection with his investigation into the therapeutic properties of the Calabar bean (Fraser TR 1863)