18 FORESTS, WOODS, AND TEEES 



of improvement in public health due to forest conditions is 

 that of the Landes in Gascony. This was formerly a bare 

 sandy tract, interspersed with marshes, and reputed to be 

 the most unhealthy region in France, the inhabitants being 

 very subject to malarial fever, scrofula, and pellagra. Since 

 about 1850 the greater part of the Landes, some 1,800,000 

 acres, has been afforested with maritime pine ; and these 

 diseases have practically disappeared, and the district is 

 now one of the healthiest in France, the decrease in the 

 death-rate being remarkable. This improvement in health 

 is no doubt due to various causes, such as the drainage of 

 the marshes, the better supply of drinking water, etc., but 

 the presence of the pine forest must be recognised as a 

 factor which has contributed to the sanitation. Even the 

 abundance of cheap firewood has a hygienic effect, as every 

 house is now free from damp all the year round, and the 

 labourers are able to dry their wet clothes. 



Parks in cities are like the forests. They do not purify 

 the air, as was formerly believed, by the functions of the 

 leaves. Nevertheless, the air in parks is purer than in the 

 dust-laden atmosphere of the streets adjoining, and contains 

 fewer bacteria. Belts of trees act as screens, and intercept 

 dust and other impurities coming from outside ; and it is 

 of some importance on this account to make a wall of trees 

 around any park or large open space in a city. 



In the preceding pages the direct effects of the forest 

 condition upon hygiene are briefly described ; but there are 

 many ways in which the presence of woods and trees affect 

 indirectly the health of the public, and these will be dis- 

 cussed in the subsequent chapters. A great deal might be 

 said in praise of the aesthetic value of forests and trees, 

 whicli influence favourably the spirits and consequently the 

 health of the people ; but a mere mention of this aspect of 

 the subject is sufficient. Few will deny its importance. 



NOTES 



1. Frank B." Kellogg, in Proc. Soc. Amer. Foresters, x. 51 (1915), says it 

 is well known among dairymen having ranches in Oregon much exposed to 



