1896.] 



45 



[Pepper. 



Special advan- 

 tages of euca- 

 lypti. Rapid, 

 gi'outh. 



densation, saturation of the diffused aqueous vapors and finally rain. 

 If, as Miguet says: "A forest is worth a mountain to produce rain," 

 then the higher and more numerous the trees, as the higher and more 

 extensive the mountain, the greater the precipitation of water, ceteris 

 paribus* Scrub growths seem to exercise little or no influence on 

 the rainfall, as witnessed in Greece, northern Africa and elsewhere, 

 where this wild vegetation is principally composed of lentisci and 

 dwarf palms, while we observe that the few million trees grown in Egypt 

 under Mehemet Ali and his successors have brought back rains unknown 

 for ages. This is doubtless a fair inference and not merely a coincidence 

 due to other, such as cosmic causes. 



Among the special advantages of eucalypti, one of 

 the most important for the colonist, who can ill afford 

 to wait long for a result from his labors, is their rapid 

 growth, as compared to that of other trees suitable to 

 this climate, excepting perhaps some acaciis mimoste, 

 as shown by the following table approximately correct 

 for an average appropriate soil and exposure : 



Age, Years. Height, Metres. Cikcumference, Metre. 



1 3 0.10 



2 5 0.15 



3 7 0.30 



4 10 0.40 



5 18 0.55 



6 15 0.75 



7 17 0.90 



8 19 1.10 



22 1.45 



25 1.60 



Moreover the trees thrive where no others will, in 

 the bad lands of these colonies, generally resisting 

 great heat, and several species withstanding relative 

 cold and even slight frosts and snows, as in Austra- 

 lia. 



To their balsamic odorf is perhaps due an antimias- 

 matic action on the surrounding atmosphere ; and 

 certainly the constant evaporation through their leaves 

 of the dampness taken up by the roots is a most im- 

 portant agent of improvement for soils needing to be drained, while these 



* Bare mountains lying in the path of damp winds naturally produce torrents and 

 landslides instead of the useful rains occasioned by wooded mountains. 



tThis balsamic exhalation from the young shoots, twigs, the leaves and fruit is due to 

 an essential oil similar to that of cajeput, which being oxidized by the air, produces 

 ozone, and which, when refined, gives eucalyptol, a sort of camphor in composition and 

 chemical properties, most serviceable as a febrifuge, tonic stimulant, aseptic and anti- 

 septic. 



9 

 10 



Resistance to 

 lieat aud to .sliglit 

 frost. 



Antiuiiasuiatic 

 action. 



