If the expenses of a great "preventive" institution--such as the Children's Aid Society--be examined, it will be found that the two thousand and odd homeless children, boys and girls, placed in country homes, cost the public only some fifteen dollars a head; the three thousand and odd destitute little girls educated and partly fed and clothed in the "Industrial Schools," only cost some fifteen dollars for each child each year; and the street lads and girls sheltered and instructed in the "Lodging-houses," to the number of some twelve thousand different subjects, or an average of, say, four hundred each night, have been an expense of only some fifty dollars per head through the year to the public. It may, perhaps, be urged in reply to this by the doubting, that all this may be true. "We admit the cheapness of prevention, but we do not see the diminution of crime. If you can show us that fewer young thieves, or vagabonds, or prostitutes, are breeding, we shall admit that your children's charities are doing something, and that the cost of prevention is the most paying outlay in the administration of New York city." To this we might answer that New York is an exceptional city--a sink into which pour the crime and poverty of all countries, and that all we could expect to accomplish would be what is attempted in European cities--to keep the increase of juvenile crime down equal with the increase of population; that the laws of crime are shown in European cities to be constant, and that we must expect just about so many petty thieves each year, so many pickpockets, so many burglars, so many female vagrants or prostitutes, to so many thousand inhabitants. We might urge that it is the duty of every friend of humanity to do his little part to alleviate the evils of the world, whether he sees a general diminution of human ills or not. But, fortunately, we are not obliged to render these excuses. New York is the only large city in the world where there has been a comprehensive organization to deal with the sources of crime among children; an organization which, though not reaching the whole of the destitute and homeless youth, and those most exposed to temptation, still includes a vast multitude every year of the _enfants perdus_ of this metropolis.