His last inspiration for general adaptation syndrome]] came from an experiment in which he injected mice with extracts of various organs. He at first believed he had discovered a new hormone, but was proved wrong when every irritating substance he injected produced the same symptoms (swelling of the adrenal cortex, atrophy of the thymus, gastric and duodenal ulcers). This, paired with his observation that people with different diseases exhibit similar symptoms, led to his description of the effects of "noxious agents" as he at first called it. He later coined the term "stress", which has been accepted into the lexicon of most other languages.