ATMOSPHERE IN RELATION TO HUMAN LIFE AND HEALTH. 285 



where the water level is high and where it is low; the mere neighbor- 

 hood of a swamp, without any pollution of water supply, is often suffi- 

 cient to prostrate troops. There can indeed be no doubt that air 

 infected from the ground very commonly causes a widespread epidemic 

 of malaria. When the waters of a flood subside, the fever extends 

 over a wide area and beyond the limits of the flood ; and exposure to 

 night air without any other source of contamination is a frequent cause 

 of fever even to the robust. Considering the large number of varieties 

 of bacilli residing in mold and in damp earth covered by sand, the 

 relation of diseases to the air and vapor emanating from the ground is 

 a subject worthy of national or international research. 



All over the world there are indications, if not such evidence as 

 amounts to proof, that where the air stagnates or is confined in valleys 

 without exposure to frequent winds, the condition of robust health in 

 a population is not well maintained. In certain valleys of Switzerland, 

 of the Pyrenees, of Derbyshire, in England, and of parts of India, 

 goiter and cretinism have been common; in low-lying clay districts in 

 England cancer has been shown to be prevalent above the average, and 

 in limestone or chalk districts to be below the average. Valleys lying 

 across the direction of the prevailing wind and not well ventilated are 

 liable to an excess of heart disease. Whether these effects are in any 

 degree due to stagnant or miasmatic air or wholly to difference in the 

 water supply it is uncertain, and the subject demands inquiry. 



Climate has often been credited, even by great writers, with effects 

 on the human constitution which statistics have failed to indicate. 

 Most people have supposed that suicide in England must be most fre- 

 quent in November or in winter when the dark foggy air depresses the 

 spirits. As a matter of fact, however, in England and in Europe, as a 

 whole, suicides are most frequent in the summer half of the year, and 

 especially in May and June, when the aspect of nature is most cheer- 

 ful and the air bright and pleasant. A very distinct and considerable 

 rise in suicides, crimes, and nervous diseases takes place in the spring 

 and early summer. The first cold weather in autumn produces a tem- 

 porary and smaller increase. Montesquieu assumed that the number 

 of suicilles is excessive in England, and attributed them to depression, 

 caused by the dark, cold, damp climate. As a matter of fact, the sui- 

 cides in England are not excessive when compared with France and 

 central Germany, and the climate is not often dark and damp for long 

 periods. Esquirol and Cabanis asserted that a rainy autumn following 

 a dry summer is productive of violent deaths; Vilemais maintains 

 that nine-tenths of suicides happen in rainy and cloudy weather. 

 Quite a different order of things is revealed by a comparison of the 

 figures for suicide, and especially for the suicide of insanity, for the 

 different months. The quick increase of the temperature of the air, 

 the dryness and sunshine of the spring have the effect of juecipitating 

 mental alienation and increasing nerve instability; the organism is 

 least robust when the winter passes away. 



