Diarrhœa is not the only disease of infancy which can be greatly diminished by improved public health administration. Tuberculosis and whooping cough and measles figure largely in the infantile death returns. Over 21 per cent. of the total deaths in infancy are due to these three diseases and to diarrhœa. The amount of syphilis appearing in the death-returns is small; but its actual amount is much greater than the figures show. If pneumonia and bronchitis, which account for 19 per cent. of the deaths in infancy, be regarded—as they should—as infective diseases, then it may be said that the problem of saving child life and securing the correlative improvement in the standard of health of children who survive to higher ages, _consists very largely in the prevention of infections_, including diarrhœal diseases and acute respiratory diseases. It follows from this that even if the limited and erroneous view be taken that Sanitary Authorities are concerned only with the prevention of infectious diseases, the reduction of infant mortality is a duty devolving on these authorities, and cannot be effectively carried out without their coöperation. Voluntary effort must therefore always, in large measure, be directed towards stimulating local authorities to perform their duties. The influence of diarrhœal summer mortality on the progress of child welfare work is further shown by the fact that among the earliest efforts were those to provide pure cows’ milk to infants. In England official Milk Depots for this purpose were never numerous; and little voluntary effort went in this direction. There now remain very few such Milk Depots; but many local authorities provide milk, more particularly dried milk, to infants for whom it is specially prescribed at Infant Consultations. Early investigations at Brighton and elsewhere showed that the mortality of infants fed on condensed milk,—chiefly of the sweetened variety,—was greater than that of infants fed on fresh cows’ milk, and directed attention to the supreme importance of domestic cleanliness in the prevention of summer diarrhœa. The Milk Depots and the concurrent agitation for purer cows’ milk served a useful purpose; though it cannot yet be said that the cows’ milk ordinarily supplied in England is satisfactorily clean.