THE ACTION OF CERTAIN ESTERS AND ETHERS OF CHOLINE, AND THEIR RELATION TO MUSCARINE

The investigation with which this paper deals started with the observation, that certain specimens of ergot and its extracts exhibited a type of action which was clearly not referabie to any of the active principles hitherto described. The action in question appeared to be of the muscarine-type, and, indeed, the search for the principle responsible for it was begun in the expectation that the muscarine would be found. The chemical procedure leading to the isolation of this principle has already been the subject of a paper by A. J. Ewins,’ who has described its identification as Acetyl-Choline, the intense depressor activity of which was already known through the work of Hunt and Taveau.2 A preliminary note on the general features of its action has also been published by myself,a and it is here only necessary to fill in the details of that account. For chemical and physiological comparison a specimen of the so-called “synthetic muscarine” or “pseudomuscarine” of Schmiedeberg and Harnack4 had been prepared, and the opportunity was taken of investigating this substance, with the result that, as elsewhere published, it was proved to be the choline-