In pressing upon the higher classes the obligation which they owe to the lower orders of society, and in urging them to assume the guardianship of the latter, the writer is not referring to vague and diffuse measures of ordinary philanthropy, but to definite and practical ones, of vast importance to the welfare of the wealthiest as well as to that of the poorest member of society. The individuals who have been most actively engaged in the stirring scenes of commercial life, are little aware, for the most part, of the rapid advances made in social science during the last twenty years, and especially within the last ten of these. Extensive as the new principles evolved in the department of mechanical discovery, during this period, have been, those in that of commercial and social activity have fully equalled them. The true method of organizing the workshop, the farm, and the manufactory, the right adjustment of capital and labor so as to secure larger advantages than heretofore to both capitalist and laborer, the just adaptation of supply and demand in community, the mutually beneficial coöperation of employer and employé, these and other questions of deep significance to the whole community have reached a theoretical, and, to a limited extent, a practical solution, which the students of social science patiently wait to communicate to the active workers in commercial or industrial affairs. For the want of this knowledge, now ready at their call, the capitalists and the employers are suffering, no less than the laborers and the employed. There is not a single department of human labor in which principles are not now known to the industrial scientist, which would enhance many fold the value of the means employed in such business, to the equal advantage of the owner of the capital and his assistants. The merchants, the bankers, the manufacturers, and the master mechanics are making a wasteful and inferior use of their material, while at the same time they are inadvertently keeping the lower classes in poverty by the want of a knowledge of these modern discoveries. It is from this lack of information only that the poor of New York, who to-day are steeped in their filth, their squalor, and their penury, are not each and all of them enjoying the comforts of a moderate competence and a decent home, the securing of which for them would have, at the same time, enhanced the wealth of the employers. The way to gain the allegiance, devotion, and fidelity of the poorer orders, is easy and simple. The problem of the harmonization of the interests of classes in community with mutual benefit to all, is scientifically solved. It only remains for the intelligent and benevolent to give due attention to the teachings of science in order to secure the most beneficial results.