Eserine, Neutral Sulphate of

This salt is obtained by saturating directly and exactly a known quantity of eserine with dilute sulphuric acid (1 in 10); or better still, by shaking a solution of the eserine with a titrated solution of sulphuric acid so as not to exceed the point of saturation. The filtered solution of sulphate of eserine is evaporated rapidly to dryne by the aid of a gentle heat. Sulphate of eserine can be crystallised in long prismatic needles, combined in radiating groups, but it is very difficult. It is preferable to preserve it in the amorphous state, and in well-stoppered bottles, as it is very deliquescent. Sulphate of eserine is employed like eserine, internally under the form of granules containing up to one milligram. It is employed also for the eyes as a solution, containing two to five centigrams of the salt to ten grams of distilled water. Solutions containing eserine, pure or combined, alter rapidly in contact with the air, becoming red; they should only be prepared in small quantities as required. (From ‘Formulæ for New Medicaments,’ adopted by the Paris Pharmaceutical Society.) See Calabar Bean .