Perhaps one of the greatest inconsistencies of an inconsistent nation lies in the fact that the extraordinary ignorance of the elementary needs of a tender infant is not confined to one section of society; it is found in Belgravia as well as in Bermondsey. Thus, though the chief sources of the tuberculosis which is responsible for the presence of 45 per cent. of the children in the London Invalid Schools are confined to the homes of the poorer classes,[109] inquiries into the incidence of rickets among children in Glasgow show a higher percentage of cases in the families of mechanics than of labourers[110]--a clear illustration that ignorance and not poverty is here the predisposing cause. Impure air and stuffy, ill-ventilated rooms are concerned in the susceptibility to both diseases, as is also malnutrition with its associated diminution of the innate powers of self-protection. But, in the one case, inability to provide suitable food is the general cause; while in the other, inexcusable ignorance of the right forms in which food should be supplied to young children is a certain source of the evil. The thought is pathetic, for the causes are wholly preventable. Pitiful also, because less excusable, is the grievous injury to health associated with a mouth full of rotten teeth, permitted as it is among families possessed of sufficient means to meet the cost of cure, who prefer to spend their money upon dress and amusement, or among the members of which necessary endurance of a trifling shock has not been cultivated. Were the foulness of the discharge from a carious tooth to be externally visible, the æsthetic instinct among the refined would clamour for prompt treatment; but, unfortunately for health, the results of the disease are concealed, and consequently condoned. Again: light, sunshine and quiet are now known to be essential to physical development and to the possession of a sound nervous system; the statement amounts to a platitude, for is not every wealthy invalid despatched to complete convalescence by the sea or in the country, and is not the custom of a general annual holiday due largely to the conscious benefits derived from an open-air life far from the bustle of towns? Yet physical morality is so poorly developed that the atmosphere of suburban as well as urban districts is permanently obscured by the preventable and wasteful results of imperfect combustion, though the detriment is incalculable to those whose lives see no change of air. The ceaseless rumble of noisy traffic, allowed to disturb the rest of thousands, or more probably of millions, of our population, is another factor responsible for the prevalence of unstable nerves and of ill-balanced brains. It assumes great gravity when it is realised that among these sleepers are numbered the children whose hours of rest are already most seriously curtailed.