I have urged the adoption of a system of notification because by this means we should undoubtedly be in a better position to control the spread of disease. I have urged it in the case of smallpox, because we may thus get patients thoroughly well isolated and by getting the persons who are likely to be exposed to the infection vaccinated, we may stop the course of this highly infectious and terrible disease; I have urged it in the case of scarlet fever because we should be thus enabled to limit its spread by preventing children who are in an infectious state attending school, by preventing the carrying on of lace and hosiery work in the very same rooms as those in which the sick person lies, and, speaking generally by preventing other heedless and unnecessary exposure of infected persons or things; I have urged it in the case of enteric (typhoid) fever, and also diphtheria, because it would enable us to make a more searching examination of the houses and premises in which cases occur, with a view to discovering unhealthy conditions than is otherwise possible, and also because we could thus secure the efficient disinfection of those particular emanations by which the disease is known to be propagated, most frequently through the recognised channels, water, milk, or sewer gas.