286 The Journal of Forestry. 



The great majority of these were sent to the lowlands, where, however, 

 except in a few instances, they have not succeeded. It seems pretty well 

 established now that this tree, contrary to popular belief, is not adapted to 

 the lowlands of the tropics. On the hills, however, as above indicated, 

 it grows with remarkable rapidity. The value of this plant on the hills, 

 consists in its importance as a timber tree, as it is not only one of the 

 most durable and useful woods, but it grows with greater rapidity and to 

 a larger size tlian any other known timber tree. Judging from the rate 

 of growth attained by plants introduced six years ago, trees two feet in 

 diameter are certainly producible in ten years from seed. Its perfectly 

 straight trunk and great length further augment the yield of timber. It 

 possesses another advantage, namely, the branches are not wide-spread- 

 ing like most other trees ; hence, in forming a plantation, the plants may 

 be set unusually thick. Compared with the growth of any other useful 

 timber tree in Jamaica, there is no doubt that the blue gum is capable 

 of producing several times more wood in an equal space of time than, for 

 instance, the Jamaica cedar {ceclrela oclorata), which is probably the 

 fastest-gvowmg Jamaica timber tree as it is the most useful, but it would 

 require double the time to produce the same quantity of wood. 



The lowest altitude at which the Eucalyptus should be planted in the 

 tropics is probably 2,000 feet. It is, therefore, greatly to be desired that 

 some of the bare grassy hills of Jamaica should be planted with this 

 invaluable tree. It seems anomalous that in a country where land is of so 

 little value, and vegetation so luxuriant, nearly all the timber used for 

 building purposes should be imported, the imports amounting annually to 

 about eight million feet of timber and five million shingles, much of which 

 is even carried to the interior of the island. 



These remarks will be read with interest, coming as they do from one 

 with the practical experience of the superintendent of the Jamaica Botanic 

 Garden. 



The Preservation of Timber. 



Buried in the earth or exposed to the air, timber rapidly deteriorates, 

 and undergoes the species of decomposition known as dry-rot. This de- 

 composition may be retarded by the application of a coat of paint to the 

 timber exposed to the air, or by carbonizing the surface of that which is in- 

 tended to be sunk in the ground. 



During the last twenty years several methods have been tried for 

 making timber more durable, the principle of which consists in expelUng 

 the sap remaining in the ligneous fibres, in order to replace it by chemical 

 solutions, such as sulphate of copper and creosote ; but these processes 

 comparatively costly and only partially successful, do not entirely accom- 

 plish their object. Starting from the fact that oak, chestnut, and certain 

 American trees resist the action of air and damp better than others, and 

 that they owe this property to the taunin which they contain, a chemist 



