310 



the French chemists who examined the new siiibst<ince reached 

 conclusions that are startlinglv similar in many ])oints to those 

 reached by modern rubber chemists. Fresneau, for instaiice, 

 thought It was a kind of condensed resinous oil ; the name now 

 used is polyterpene. To prevent it from sticking he used Spanish 

 white, ashes or dust. 



" La Condamine induced other explorers to search for rubber 

 and learned before he died in 1775 that it had been found in the 

 Isle de France and in Madagascar. Xcvertheless, the only practical 

 commercial use found for tlic caoutchouc in that century was as an 

 eraser of pencil marks, whicli led to Priestley's christening it by the 

 name it has retained in English, " india rubber ''." 



T. F. C. 



How to Destroy L&rge Jungle Trees. 



Iji clearing the jungle from an estate it is ol'ten a great source 

 of trouble and expense to get rid of the large jungle trees. Too 

 often does one see their stumps and roots remaining, a ready centre 

 of fungus infection to the rubber trees just when they are begin- 

 ing to bear at their best. The following note taken from the In- 

 dian F'orester, May, 1920, may be of assistance to those about to 

 clear jungle. Of course this method can only l)e employed whilst 

 the tree is yet living. 



" AVhere it lis desired to destroy a tree without cutting it down, 

 a hole is liored in the tree in a downward direction to the centre. 

 For large trees an inch auger is used : for smaller ones ^ inch size 

 is large enougli. For large trees 1 oz. to 2 oz. of ordinary com- 

 mercial salt^^etre (nitrate of potash) is used, and for smaller ones 

 I oz. to 1 oz. A plug is put into the hole to keep the rain from 

 washing ft out. The nitrate of po'tash is carried by the sap to the 

 tips of the branches and the rootlets. If the tree is a large one, 

 say, 2 feet or more in diameter, very little difference will be noticed 

 in the foliage for 2 or 3 months, then the leaves begin to fall, and 

 it assumes a l>are wintry appearance. x\t the end of about 6 or 8 

 months a little brushwood is piled around the tree and lit; it will 

 smoulder away to the remote ends of .the roots, sometimes 30 feet 

 away from the tree, leaving masses of valuable ash; the tree will 

 fall, and when fallen it will continue to smoulder until every 

 l>article is convei*ted into ash. — ["A Hand-book of Forestry" by 

 A. I). Webster.] " 



T. F. r. 



