The inventor does not set this up as a perfect digestive system capable of manufacturing blood and nourishing juices to support the animal, and it would be unfair to reproach him with this shortcoming. He claims only to imitate the mechanics of the digestive process in three things, firstly, the swallowing of the food, secondly the maceration, cooking or dissolving of it, and thirdly the action causing it to leave the body in a markedly changed form….
It was necessary to employ different methods to get the artificial duck to take the grain, to transfer it to the stomach and here inside a small space to construct a chemical laboratory where the principal part of the food could be decomposed, and then through a network of tubes to dispose of the food when required from the other extremity.
— Automate, L'Encyclopedie / Dictionnaire des Sciences, 1777; qtd. in Alfred Chapuis and Edmond Droz, Automata: A Historical and Technological Study, tr. Alec Reid (Editions du Griffon, 1958)