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fruit and other trees is due either to injurious atmos- 

 pheric or meteorological causes, to insects, or to 

 fungoid growths. 



The first may no doubt have, in certain cases, 

 much to do with it ; as for instance, an excess or a 

 deficiency of ozone in the air, which by its remarkable 

 oxidizing power may matterially affect the various 

 chemical changes going on in the organization of the 

 plant. Lest some of Mauritian inhabitants may not 

 fully understand what this mysterious agent is, I will 

 state on the authority of Prof. Duuglison, that ozone 

 is a power fully odorus matter, produced when a 

 current of ordinary electricity passes from pointed 

 bodies into the air. 



It is generally presumed to be a peculiar modi- 

 fication of oxygen ; and in varying quantity in the 

 atmosphere is supposed to affect the health of man. 



By others, ozone is considered to be oxygen con- 

 densed to I its bulk, when it possesses remarkable 

 oxidizing properties. It can be artificially produced 

 by placing phosphorus in a flask filled with atmos- 

 pheric air and partly covered with water, occasionally 

 agitating the flask. So, too, occasional change in the 

 normal condition of the atmosphere hy an excess of 

 deficiency of its gaseous constituents, or the presence 

 of the gazes, may induce cachexia. In the full grown 

 human being the lungs expose 1,400 square feet of 

 surface to the action of the air inhaled. Large as this 

 surface is, that of a good sized tree, through its leaves, 



