22 Is the Eucalyptus a Fever-destroying Tree ? 



down at starting, the question now lies before us — Is the 

 eucalyptus a fever-destroying tree ? 



We have observed that the physical geography of 

 Australia differs in no way from that of other countries. 



That the vegetation is specially its own. 



That it contains peculiarities and principles adapted to 

 benefit a country. 



That to judge of its effect on climate, malaria, or fever 

 germs, the physical and chemical characters of this vegeta- 

 tion must be considered. 



Physically. — 1st. Its powerful root action as an absorbent 

 of humidity from the earth, by being an evergreen, and so 

 continuous in its work. 



2nd. Its leaf formation and presentation. 



3rd. The abundance of leaf surface. 



4th. Its leaf evaporation of water, oil, and acid, under a 

 perpetually genial temperature. 



Chemically. — 1st. Its volatile oil. 



2nd. Its volatile acid. 



3rd. Their power of producing peroxide of hydrogen. 



And finally — The evidences of the abundance of these 

 volatile bodies, both in the plant and in the air. In the 

 plant — By experiments conducted on one or more of the 

 species throughout all seasons of the year, and almost con- 

 tinuously since 1853. In the air — By the sense of smell and 

 by morphological deductions. 



From all this we gather that there is an active agency 

 existing in our vegetation over that of other countries. 

 That whatever change may take place in the condition of the 

 atmosphere, arising from the free and large supply of these 

 chemical bodies in the air, it is from all known evidence of 

 an invigorating and healthy nature and character. 



The various fever types as found existing amongst us a^ 

 times appear malignant, arising either from importation or 

 from the existence of bad sanitary regulations ; but medical 

 testimony is that their virulence is meteor-like, " dies at its 

 opening day." No credit can be taken for any improved 

 sanitary condition of our surroundings by ourselves in our 

 towns and cities, the influences operating there entice the 

 poison fever germ to fructify and abound. 



" Death lives where power lives unused," and were it not 

 that such happy and benign influences, as those exerted by 



