116 THE HUMAN SIDE OF TREES 



until it is taken away, the sudden disappearance of 

 the tree-product caoutchouc from the face of the 

 earth would work strange havoc. With a tire-less 

 car the joys of automobiling would be flown for- 

 ever. With an unrubberised raincoat and no feet 

 protectors London would become uninhabitable. 

 Without rubber insulation to work with, electrical 

 engineering would be set back ten years. Sans 

 rubber tubing and a hundred other contrivances, 

 the medical profession would be at a complete 

 standstill. What would childhood be minus rubber 

 balls, rubber boots, and rubber balloons? What 

 would manhood be like with wooden fountain pens, 

 steel pencil erasers, and paper garters? 



In a sense rubber or caoutchouc might be con- 

 sidered a by-product, as the various tropical trees 

 from which it comes secrete it in the form of a 

 milky liquid which seems to be non-vital in the 

 life of the manufacturer. The physical structure 

 of this juice is as much like milk as it looks. 

 Minute globules of rubber constitute the cream. 

 They rise to the top and can be skimmed off. The 

 usual way is to boil the entire liquid down until 

 it becomes solid enough to be shaped into cakes. 

 Recently a centrifugal machine which in operation 

 is much like a cream separator has been introduced 

 into the rubber fields. Much has been written about 



