58 



LETTERS ON TREES. 



giant, calculated by its rings, is 2520 years. This king 

 of the forest is to be girdled, and the operation has 

 already commenced. The bark — which at the foot is 

 nearly fourteen inches thick — is to be taken off in 

 fragments up to the height of fifty feet, and sent to 

 the Universal Exhibition in New York." * 



7. Then there is the famous Boabab (the Adansonia 

 digitata) growing in Senegal, and supposed to be the 

 oldest kind of tree in any part of the world. The 

 trunk of this extraordinary tree does not attain a height 

 much exceeding fifteen feet, but in some instances it is 

 from eighty to ninety feet in girth. And, according 

 to the estimate of Adanson, founded on a comparison 

 of Thevet's account of one seen by the latter in the 

 year 1555, with his own measurement of the same tree 

 two hundred years later, the trees that are twenty- 

 seven feet in diameter have an age of 4280 years. 

 Some of them have a diameter of thirty feet, and these 

 are supposed to have attained an age little short of 

 6000 years. 



8. Coeval probably with the Boabab is the Gum- 

 Dragon Tree {Dracoena Draco), which furnishes the 

 astringent resin called dragon's blood, once used in 

 medicine, but now chiefly by painters as a red varnish. 

 Of this tree there are two specimens in the Palm- 



* Communicated to the Heraldo " of Sonora, by a correspondent 

 '^who lately went to see this prodigy of the vegetable kingdom." — 

 Aberdeen Herald newspaper, 1853-4. 



