but also contribute to the scattering of population over wider areas. The most potent factors in attracting people to the cities were, in former times, the commercial facilities they afforded, with opportunities to obtain employment in trade, and are now the opportunities for employment in trade and in manufacturing industries. The cities, however, do not grow merely by accretions from the outside, but they also enjoy a new element of natural growth within themselves in the greater certainty of living and longer duration of life brought about by improved management and ease of living in them, especially by improved sanitation, and it is only in the nineteenth century that any considerable number of cities have had a regular surplus of births over deaths. Migration city-ward is not an economic phenomenon peculiar to the nineteenth century, but is shown by the study of the social statistics and the bills of mortality of the past to have been always a factor important enough to be a subject of special remark. It is, however, a very lively one now, and "in the immediate future we may expect to see a continuation of the centralizing movement; while many manufacturers are locating their factories in the small cities and towns, there are other industries that prosper most in the great cities. Commerce, moreover, emphatically favors the great centers rather than the small or intermediate centers." In examining the structure of city populations, a preponderance of the female sex appears, and is explained by the accentuated liability of men over women in cities to death from dangers of occupation, vice, crime, and excesses of all kinds. There are also present in the urban population a relatively larger number of persons in the active period of life, whence an easier and more animated career, more energy and enterprise, more radicalism and less conservatism, and more vice, crime, and impulsiveness generally may be expected. Of foreign immigrants, the least desirable class are most prone to remain in the great cities; and with the decline of railway building and the complete occupation of the public lands the author expects that immigrants in the future will disperse less readily than in the past, but in the never-tiring energy of American enterprise this may not prove to be the case. As to occupation, the growth of cities is found to favor the development of a body of artisans and factory workmen, as against the undertaker and employer, and "that the class of day laborers is relatively small in the cities is reason for rejoicing." It is found "emphatically true that the growth of cities not only increases a nation's economic power and energy, but quickens the national pulse.… A progressive and dynamic civilization implies the good and bad alike. The cities, as the foci of progress, inevitably contain both." The development of suburban life, stimulated by the railroad and the trolley, and the transference of manufacturing industries to the suburbs, are regarded as factors of great promise for the amelioration of the recognized evils of city life and for the solution of some of the difficulties it offers and the promotion of its best results.
Dr. James K. Crook, author of The Mineral Waters of the United States and their Therapeutic Uses, accepts it as proved by centuries of experience that in certain disorders the intelligent use of mineral
- Mineral Waters of the United States and their Tlierapeutic Uses, with an Account of the Various Mineral Spring Localities, their Advantages as Health Resorts, Means of Access, etc.; to which is aided an Appendix on Potable Waters. By James K. Crook. New York and Philadelphia: Lea Brothers & Co. Pp. 588. Price, $3.50.