exhalation; how, in the spongy stratum of decaying vegetable 

 remnants, they retain far more humidity than even cultivated 

 soil; how they with avidity re-absorb the surplus of moisture 

 from the air, and refresh by a never- wanting dew all vegeta- 

 tion within them and in their vicinity, has been explained, not 

 only by natural philosophy, but also often by observations 

 of the plainest kind. How forest-trees, by the powerful 

 penetration of their roots, decompose the rocks, and force 

 unceasingly from deep strata the mineral elements of vegetable 

 nutrition to the surface; how they create and maintain the 

 sources for the gentle flow of watercourses for motive power, 

 aqueducts, irrigation, water traffic and navigation ; how they 

 mitigate or prevent malarious influences of all this we 

 become cognisant by daily experiences almost everywhere 

 around us. We have to look, therefore, far beyond a mere 

 temporary wood supply, when we wish to estimate the bless- 

 ings of forest vegetation rightly; and our mind has to grasp 

 the complex of causes and sequences originating with and 

 depending on the forests, before their value as a total can be 

 understood. 



" Here, in the sultriest season, let us rest : 



Fresh is the green beneath those aged trees ; 

 Here air of gentlest wing will fan our breast 

 From heaven itself we may inhale the breeze." 



BYRON. 



Let us then take timely warning; let us remember that 

 denuded earth parts with its warmth by radiation, and is 

 intensely heated by insolation ; that thus in woodless countries 

 the extremes of climate are brought about in rendering the 

 winter-cold far more intense and boisterous, and the summer- 

 heat far more burning and oppressive. Let us remember why 

 the absence or destruction of forests involves periodic floods 

 and droughts, with all the great disasters inseparable there- 

 from. Let us bear in mind that even in our praised Australia 

 many a pastoral tenant saw his herds and flocks perish, and 

 even the very kangaroos oft 7 his run; how he looked hopefully 

 for months and months at every promising cloud which drew 

 up on the horizon, only to dissolve rainless in the dry desert 

 air; whereas when the squatter's ruin was completed, the last 

 pasture parched, and the last waterpool dried up, great 

 atmospheric changes would send the rain-clouds over the 

 thirsty land with all the vehemence of precipitation, and 

 would convert dry creeks into foaming torrents, or inundate 

 with furious floods the very pastures over which the carcases 



