Addison, Thomas (1793–1860), English physician. Regarded as the father of modern endocrinology, Addison inaugurated the study of internal secretion and the endocrine glands. With John Morgan, he wrote the first book in English on the action of poisons in the living body, and he was the first to use static electricity in the treatment of spasmodic diseases. In 1849 he published a preliminary description of adrenocortical insufficiency. In an 1855 monograph he gave a full, classic description of this syndrome and an equally classic description of pernicious anemia. Shortly afterward, the French physician Armand Trousseau named these two diseases Addison's disease and addisonian anemia. Addison also produced original and significant works on tuberculosis, pneumonia, and skin disease.