Dr Henry C. Allen, M.D., was born on October 2, 1836, in the village of Nilestown near London, Ontario. He studied medicine at the College of Physicians and Surgeons in Ontario, Canada and received his homoeopathic training at Western Homoeopathic College (AKA Cleveland Homoeopathic College) in Cleveland, Ohio where he graduated in 1861. In 1892, Allen helped found the Hering Medical College and was Dean and Professor of Materia Medica until his death. Dr Allen passed away on January 22, 1909.The work of a homoeopathic student while studying and applying materia medica is to constantly compare and differentiate the pathogenesis of a remedy with the recorded anamnesis of the patient; one must differentiate between the apparently similar symptoms of two or more medicinal agents in order to select the simillimum.Key Features:- Peculiar, uncommon or sufficiently characteristic symptoms in the polychrest remedy used as a pivotal point of comparison Knowledge to grasp the PQRS symptoms immediately. Knowledge of the individuality of each remedy and the symptom.