In 1829 Dr. Addison published, in conjunction with John Morgan, Surgeon to Guy’s, an essay on “The Operation of Poisonous Agents on the Living Body.” Strange to say, this was the first serious investigation in England into the phenomena of general poisoning. The authors believed that a direct influence on the nerve filaments distributed to the blood-vessels accounts for the rapid effects of some of them. In 1830, Addison published a pamphlet on some disorders of females, vigorously combating some received notions, and objecting to the system of depletion. In concluding a lengthy lecture to his class on this subject, he showed the sentiments which animated him by the following remarks: “Gentlemen, if you require an apology for detaining you so long, I find ample material for that apology in the lively interest in which we must all feel in the comfort and happiness of the other sex, doomed as they are, both by the decrees of Providence and by human institutions, to drink deep of the bitter cup of suffering. Whatever may be her lot in this world, we, as men, must at least acknowledge that, whilst Infinite Power gave us being, Infinite Mercy gave us women.” In 1837 Addison was elected full Physician to the Hospital, and was appointed joint-lecturer with Dr. Bright on Medicine. About this time he commenced with his colleague the “Elements of the Practice of Medicine,” of which the first volume only appeared, chiefly written by Addison. It was most highly valued, but neither author could be induced to complete it. Valuable monographs in number came from his rich experience: two on Pneumonia in 1837 and 1843; Observations on the Anatomy of the Lungs in 1840; the Pathology of Phthisis, 1845, in which he laid down the principle that inflammation constitutes the first instrument of destruction in every form of phthisis. This early advocacy of a doctrine which has thrown much light on this disease was strongly opposed by the physicians of his day, and stamped Addison as a powerful innovator. He was much impressed by Laennec’s views, and acquired very great power of diagnosing from auscultation of the chest. Yet, candid ever in confessing ignorance, he read a paper before Guy’s Physical Society in 1846, “On the Difficulties and Fallacies attending Physical Diagnosis of Diseases of the Chest.” Among other subjects, he dealt with Diseases of the Liver, Affections of the Skin, Disorders of the Brain connected with Diseased Kidneys, and “the Influence of Electricity as a Remedy in certain Convulsive and Spasmodic Diseases,” in every case bringing together facts hitherto disconnected, and contributing markedly to advance medicine as a science.