EUCALYETUS TREES. 137 



to remain retained in the cortical layer without de- 

 conaposition, while in the ordinary three years' bark 

 half or more of these principles is lost. 



Facts like these lead us to appreciate the important 

 bearings of the natural sciences on all branches of in- 

 dustry ; but they warn us, also, to pause before we 

 give our further consent to the unlimited and reckless 

 demolition of our most accessible forest lands, on the 

 maintenance of which so many of our industries de- 

 pend. 



Just as it required, even under undisturbed favor- 

 able influences, centuries before our forest riches were 

 developed to their pristine grandeur, so it will need, 

 in the ordinary laws of nature, at least an equal 

 lengthened period before we can see towering up again 

 the sylvan colosses, which eminently contributed to 

 the fame of the natural history of this land-— if, indeed, 

 the altered physical condition of the country will ren- 

 der the restoration of the trees on a grand scale, possi- 

 ble at all. 



Has science drawn in vain its isothermal girdles 

 around the globe, or has the searching eye of the 

 philosopher in vain penetrated geologic structure, or 

 in vain the exploring phytographer circumscribed the 

 forms ? Well do we know what and where to choose; 

 botanic science steps in to define the objects of our 

 choice, which other branches of learning teach us to 

 locate and rear. 



The Tea would as thriftly luxuriate in our wooded 

 valleys as in its native haunts at Assam, and yield a 

 harvest far more prolific than away from the ranges. 

 Indeed, we may well foresee that many forest slopes 

 will be dotted in endless rows with the bushes of the 



