cestry to the ghettoes of old fortified European cities ; liis susceptible an- 

 cestors have been killed off to such an extent that he is largely immune 

 to unsanitary conditions found in our cities. But he can not thrive under 

 extreme conditions, such as are found in Asiatic cities, nor does he try 

 to. Being ambitious he gets out of our own slums as quickly as possible. 



On the other hand are the descendants of Southern Mountaineers, the 

 latter a class of people who for several generations have lived in isola- 

 tion, under so-called healthful surroundings, with an almost complete 

 abatement of the weeding-out process found in cities. When they go to 

 crowded, smoky and dusty cities they quickly fail. There may be com- 

 plete failure, that is death, or failure of health with much ill health,! 

 the ill health attendant upon the proce.ss of adaptation. One can not 

 ])roperly speak of this as disease but as a reaction to an abnormal, an 

 unsanitary environment. 



Country-bred man goes to the city with a "stock of health." This in 

 time fails, quickly in some, slowly in others ; it may suffice for an indi- 

 vidual but not for descendants and then we hear of race suicide. 



Children bom of city parents may perish at once or they may live 

 for weeks, months or years and then die, perhaps after having had much 

 il) health which finally terminates in disease. Certain diseases must be 

 regarded as city and house diseases par excellence. 



Just where health shades off into ill health, into minor maladies, and 

 then into disease and death, is always an interesting study to the student 

 of environmental influences, not to speak of the student of pathology. 



Ill health touches many of us or our relatives or friends. Well- 

 defined disease is comparatively rare, it may not appear until near the 

 end of life. We should sharply discriminate between ill health and dis- 

 ease. 



Some diseases have a rapid onset and may be fatal in a few hours, 

 but as a rule the onset is slow and announced by preliminary warnings. 

 Change of environment, making the conditions favorable for the body, 

 may mean a continued existence. 



Some diseases must be considered incident to city life and indoor 

 life, notably tubex'culosis and pneumonia — diseases with a frightful mor- 

 tality. Then there is a host of minor maladies which must be looked 

 upon as "diseases of civilization" — we need only think of catarrh, dysr 

 pepsia and nervous prostration. 



[27— ?9034] 



