This section is from the book "A Text-Book Of Pharmacology, Therapeutics And Materia Medica", by T. Lauder Brunton. Also available from Amazon: A text-book of pharmacology, therapeutics and materia medica.
Characters. - In colourless or pinkish crystals.
Reactions. - The aqueous solution has an alkaline reaction; when warmed with or when shaken with dilute solution of potash it becomes red, and when evaporated to dryness over a water-bath it leaves a bluish residue, the acidified solution of which is beautifully dichroic, being blue and red. Physostigmine causes contraction of the pupil of the eye.
1/1000 th gr. in each.