426 ANNUAL EECORD OF SCIENCE AND INDUSTRY. 



will be complete, as in the other case. 18 (7, July 16, 1873, 

 464. 



THE INFLUENCE OF FOEESTS ON OZONE. 



The elaborate report of Ebermayer on the physical influ- 

 ences of forests on the air gives the following, with reference 

 to ozone, as the result of extensive observations made in 

 Bavaria. In the open fields the air is richest in ozone, as also 

 in the neighborhood of seas, and, in general, in places with 

 great atmospheric moisture. In high places, it is usually 

 richer than in the lowlands. There is more ozone in the 

 air in forests and their neigrhborhood than in those resjions 

 distant therefrom; but in the interior of a room, or space in- 

 closed with wood, the quantitj'- of ozone w^as not greater; on 

 the contrary, somewhat smaller than in the open field im- 

 mediately in the neighborhood of forests. In the upper 

 stratum of air within the branches of a tree, where the leaves 

 are thickest, the air of the forest was always richer in ozone 

 than in the lower stratum five feet above the ground: a 

 phenomenon that apparently results from the fact that ozone 

 is absorbed by the decaying vegetable matter on the ground. 

 During heavy fog, the quantity of ozone is small, and often 

 nothing at all. Similarly, only a slight coloring of ozone pa- 

 per is remarked with continuous north and northwest winds, 

 and beautiful dry weather. The change of wind to south or 

 southwest brings about a decided ozone reaction, which is, 

 indeed, always strongest on warm, stormy, rainy days. Dur- 

 ing high winds, the ozone reaction is greater than when light, 

 and the air is rich in ozone during thunder and snow storms. 

 Zeitschrift fur Meteorologie, 256. 



