The present article is in part a review of the development of previously reported chemical assay methods for ergot and ergot fluidextract (1). Certain miscellaneous data, subsequently determined while cornleting this study, are reported for the first time. The p‐dimethylaminobenraldehyde color reaction has been examined and its reliability confirmed. Ergonovine maleate has been found a more stable reference standard than ergotoxine ethanesulfonate. The assay methods have been subjected to further collaborative study, following minor revisions, and the results are reported and discussed.