STRANGE PLANTS AND TITEIB WAYS. 51 



7. With all its utilities, the eucalyptus is most widely 

 known for its sanitary qualities. From observation and 

 experiment, it seems to deserve the name by which it is 

 often known — the fever-tree. Its hygienic qualities have 

 long been known in Australia, and this has led to exten- 

 sive plantings in malarious regions where the climate will 

 permit their growth. They are semi-tropical, and the 

 ordinary varieties can not endure the cold. They flour- 

 ish well in California, and in other like warm regions. 

 A plantation in Algiers cleared a region of miasma where, 

 previous to its introduction, the French garrison had to 

 be changed every five days on account of malaria. Some 

 of the most unhealthful parts of the Oampagna near 

 Rome have been rendered inhabitable by the eucalyptus 

 groves. 



8. The sanitary effects of the eucalyptus are twofold. 

 From the peculiar structure of its leaves, as above shown, 

 it has an enormous pumping power, it being estimated 

 that a tree will eliminate from a swampy soil eight times 

 its own weight in water every twenty-four hours. This 

 moisture is delivered to the atmosphere in the condition 

 of pure water, all deleterious substances being strained 

 out by the tissues of the wood. In addition to this health- 

 ful drainage, the aroma of the leaves acts beneficially in 

 two ways : first, by directly furnishing an invigorating 

 tonic through the lungs, and, second, by creating ozone, 

 and thus indirectly stimulating healthful action of the 

 nerves and tissues. 



9. The demonstrated value of the eucalyptus has made 

 its spread very rapid, so that it now has become quite com- 

 mon in all civilized countries where the conditions are fa- 

 vorable to its growth. By care in cultivation, it will doubt- 

 less in time become acclimated to colder regions. But 

 restricted as it now is, its value is so great that it may be 

 considered as the great tree of the future. 



