LUTHER BURBANK 



But with the modern tendency to apply scientific 

 methods to forestration in general, doubtless the 

 question will ultimately arise as to whether the 

 turpentine trees may not be improved along with 

 the timber producers. 



That trees of the same species differ quite 

 radically in the amount of the valuable juices is 

 certain, so there would appear to be no reason 

 why it may not be possible to develop varieties of 

 trees that will be conspicuous for this quality, just 

 as other trees have been improved as to their 

 powers of growth or their capacity to produce 

 abundant crops of fruit. 



VARIED PRODUCTS OF THE PLANT LABORATORY 



An incidental use of the resinous exudate of 

 the pine tree that has come to assume considerable 

 economic importance is the production of chewing 

 gum. 



The habit of gum chewing appears to have 

 originated or at least to have gained chief popu- 

 larity in America in comparatively recent times. 

 The resin that exudes from the spruce was the 

 substance that was chiefly used, under the name of 

 spruce gum, until somewhat recently. But of late 

 years the chewing gum industry has reached pro- 

 portions that make it impossible to meet the 

 demand from this source. And it has been found 

 that ordinary resin, combined with sugar and lin- 



[2581 



