Apollinaire Bouchardat (1806-1886) begins its hospital formation by the pharmacy internship and then starts his medical studies. He becomes chief pharmacist of the Hôtel-Dieu in 1835 and during 20 years, he devotes his life to the study of diabetes. Through observations and experiments, he builds new concepts allowing to establish the bases of clinical diabetology due to a solid competence in fundamental sciences and his intelligence in semiologic observations. He studied urine glucose as a reflect of the clinical state of the patients and, in order to carry out its exact measurement, he recommended the use of the polarimeter. He engaged himself in many studies concerning well as the patients diet as to their way of life. Thus he recommended a large decrease in starchy foods and sugars, he encouraged physical exercise and considered that, since the assumption of responsibility of the diabetic was serious, it could foresee the remission of disease. Due to encouraging results, he developed self-monitoring by the patients by the means of simple chemical reagents, convinced that making patients responsible, despite difficulties of the diet, could modify their attitude. Precursor of the modern diabetology, one can consider that he founded it as a true medical discipline. Its major work: De la Glycosurie ou diabète sucré, son traitement hygénigue is pro-bably the first textbook on diabetes, associating clinical observations, experimental steps and proposals for a treatment based on the patients' way of life: mainly diet and exercise: still preached steps, a hundred and fifty years later.