AUSTIN ÓMALLEY. {88} VII SOCIAL MEDICINE The influence of the clergyman or the charitable visitor in matters of health and sanitation can scarcely be overestimated. The removal of prejudices with regard to sanitary regulations for the prevention of disease and modern advances in the treatment of disease is an important social duty. There is no doubt that if this influence be properly directed, sanitary measures of various kinds will be much more readily enforced and the precautions necessary to prevent the spread of serious infectious ailments more faithfully observed. As this amelioration of sanitary conditions will affect mainly the poor, lessening their suffering and adding to their possibilities of happiness, its accomplishment becomes a great Christian duty, obligatory on all those who are interested in the uplifting of the poorer classes. Professor Virchow, the distinguished German pathologist, used to say that popular medicine was in all ages at least fifty years behind scientific medicine. He had himself discovered the principles of cellular pathology nearly half a century before his death, yet he declared that the popular mind still believed in the old doctrines of humoral pathology,--that is, that the conditions of health and disease depended on the constitution of the fluids of the body (the blood, the bile, the mucus, and so forth), and had not generally accepted modern advances in medical knowledge of the underlying basis of disease in the solid tissues. There is no doubt that many old-fashioned notions long since discredited by physicians are still very generally accepted by the popular mind, and even the intelligent classes sometimes harbour convictions with regard to the good or evil effects of habits {89} of life, diet, and the operation of drugs of various kinds that are entirely contrary to present-day medical knowledge.