I now proceed to submit the reasons for believing that the immediate expenditure of so much money as would be incurred by the adoption of such of the remedial measures as appear to be available by the agency of any public administration would be sound measures of immediate economy, and of ultimate public gain: and also the grounds for believing that the same conclusion is applicable to the cost of those measures of prevention which, though directly or indirectly controllable by legislative authority, are within the province of private individuals to execute, such as the construction of the dwellings of the labouring classes. VI.—EVIDENCE OF THE EFFECTS OF PREVENTIVE MEASURES IN RAISING THE STANDARD OF HEALTH AND THE CHANCES OF LIFE. On viewing the evidence, which shows that, in most situations higher chances of life belong to the middle and higher classes of the population, an impression may be created that the higher standards of health are essentially connected with expensive modes of living. The highest medical authorities agree, however, that the more important means for the protection and advance of the health of those classes must be in still further reductions than those which it is the present tendency in the higher classes of society to make of the use of highly stimulating food. The evidence already adduced with respect to the labouring classes in the rural districts and those living on high wages in towns, will have gone some way to remove the erroneous impression with respect to them, and it admits of proof that a higher standard of health and comfort is attainable for them even at a less expense than that in which they now live in disease and misery. The experience of the effect of sanitary measures in the royal navy may be adduced as evidence of the practicable standards of health consistent with great labour and exposure to weather obtained at a cost not higher than that within the wages of ordinary labourers. The experience of the effects of sanitary measures in banishing spontaneous disease from crowded prisons, offers further evidence of the health obtainable by simple means, under circumstances still more unfavourable.