_Diet._—The doctrine has been growing among the laity that the child’s likes and dislikes should determine what food it should eat. Thus a finical taste is cultivated and a lack of proper nourishment follows, and it is this finical diet class of people which forms a large percentage of tuberculous invalids. It has long been recognized that a proper diet and the tolerance of it is of the utmost importance in the treatment of tuberculous patients, but from the foregoing it would appear that a proper diet throughout life is also of the utmost importance in the prevention of disease; a sufficiency, not only as to quantity, but also as regards variety. It is the patient who can eat everything who stands a good chance of getting well. So, too, it is the individual whose diet for years has been perverse, who could not eat meat, to whom eggs were distasteful, who could not stand milk, who was infected with the vegetarian fad, or the two-meal-a-day fad, who stands a fair chance of falling a victim to tuberculosis, through a lowered tone of the system, because it offers but a feeble resistance to a powerful and insidious enemy. And the mode of the preparation of the food is an equally important factor. It has been shown that the poor cooking among the lower classes is a powerful predisposing cause to intemperance and tuberculosis. Influenza is a frequent and important agent in bringing to light latent tuberculosis, and must be classed as an important exciting if not predisposing cause. Low, damp climates predispose to the infection by lowering the vitality. Tuberculosis is more prevalent in cities than in rural communities, due to the manner of housing and the character of the occupation. _Summary of the Present Views of Infection._—The doctrine of inherited and acquired susceptibility still holds sway; next, that all infants are susceptible, and that susceptibility lessens with increase in age; that adults are comparatively insusceptible when free from general and local lowered resistance and repeated and prolonged exposure. As to the source of infection, the consensus of opinion and ascertained facts point to the sputum as of overwhelming importance; cow’s milk is an important factor; the food may be infected directly by coughing, or the dirt and dust from the floor and hands; the fingers and many other objects that find their way into the child’s mouth are sources of danger. To adults, both dust and moist droplets are more often the source of infection than infected food. _Expectoration._—Careless expectoration is the chief source of infection. Laws should be passed and enforced prohibiting the expectoration on pavements, stairways, in all public conveyances, and all public places.