SCIENCE 



Peidat, Mat 27, 1910 



CO'NTE'NTS 

 Cotistructive Community and Personal Hy- 

 giene: Db. Luthee Haxset Gulick 801 



The Research Laboratory of Physical Chem- 

 istry of the Massachusetts Institute of 

 Technology 810 



Scientifie Notes and News 811 



University and Educational News 815 



Discussion and Correspondence: — 



Weismannism,, a Criticism of Die Seleh- 

 tionstheorie : Db. A. E. Oetmann. Note on 

 the Marking System in the Astroiiomical 

 Course at Columbia College: Peofessoe 

 Haeold Jacobt. The Definition of Force: 

 Wm. Kent 815 



Scientific Books: — 



Shackleton's The Heart of the Antarctic: 

 General A. W. Gebelt 822 



Special Articles: — 



Prediction of Belatioiiships among some 

 Parasitic Fungi: Feank D. Keen. The 

 Miocene Horizons at Porters Lamding, 

 Georgia: Db. T. Wayland Vaughan .... 830 



The Atnerican Society of Zoologists, Central , 

 Branch: Peofessoe H. V. Neal 834 



Societies and Academies : — 



The Anthropological Society of Washing- 

 ton: I. M. Casanowicz. The Michigan 

 Academy of Science, Section of Zoology: 

 R. W. Hegnee 839 



MSS. intended for publication and books, etc., intended for 

 review sbould be sent to the Editor of Sciekce, Garrison-on- 

 Hudson, N. Y. 



CONSTRUCTIVE COMMUNITY AND PER- 

 SONAL HYGIENE ' 



I. The Community 



The need of constructive work in med- 

 icine applies to the community as well as 

 to the individual. The steady growth of 

 American cities — in fact, of the cities of 

 the world— indicates that we are to become 

 in the not far distant future predomi- 

 nantly a city people. The accompanying 

 diagram (A) shows how the rural popu- 

 lation has been steadily falling and the 

 urban population steadily rising since 

 1880 in all five census divisions of the 

 United States. In Massachusetts, during 

 the same period, there has been an abso- 

 lute decrease of some thirty thousand in 

 the rural population, while the urban 

 population has increased by over one mil- 

 lion. This is shown in graphic form in 

 diagram B. The remarkable growth of 

 the cities appears more graphically still 

 in the diagram (C) showing the growth 

 in the urban proportion of the population 

 during the past eleven decades. 



The causes of this steady urbanization 

 of our kind are not far to seek. Three 

 sets of causes may be read by him who 

 runs. First is the economic cause. Owing 

 to the use of machinery, an ever smaller 

 fraction of our people can be engaged in 

 the production of enough raw material to 

 supply the needs of the world. To pro- 

 duce more than this is to invite economic 

 disaster. Hence a progressively large 

 fraction of the people will be engaged in 



^ An address delivered at the College of Physi- 

 cians and Surgeons, New York City, April 14, 

 1009, in the course of Columbia University lec- 

 tures on sanitary science and public health. 



