Within the last few decades, it is perfectly true, the strides that have been made towards the ultimate sanitary perfection of living are enormous. Vast sums of money are quite properly spent annually on securing for town and country dwellers alike, in answer to the demands made by scientific investigators into the theory of microbes, pure water supplies, ventilation and light in dwelling-rooms, systems of drainage and disinfectants, and inspections of food which shall reduce, as far as possible, such dangers as are universally incident to life and health. Yet in a way, admirable as such expenditure and research is, admirable also as are the results which have followed it, these natural provisions for health deal more with the surroundings of the body than with the body itself. Tenement houses are built on the most approved sanitary principles, but that done it is left to the discretion of the inhabitants of them (provided they do not keep pigs or poultry in their bedrooms) to decide as to how they shall live in them. Board schools are built with rooms containing so many cubic feet of air per person, but that done the teachers are allowed to keep the windows hermetically closed. Inspectors of food, again quite properly, destroy barrows of decaying fish, and impose fines on their vendors, but no instruction is given to either rich or poor as to the nature of foods, and in consequence, with the best will in the world, they take quantities of an expensive and stimulating food, when what they really need is a cheap and nutritious one. Interesting and costly experiments are made as to the bacilli of various diseases, and numberless means of dealing with them are suggested in text-books, but what is not done is to inform people, except in the vaguest manner, as to how they may prevent such bacilli finding a suitable, nay a possible, home in their bodies.