412 QUEENSLAND AGRICULTURAL JOURNAL. 1 May, 1898.] 
one of the most remarkable and important trees in the whole world. The yield 
of yolatile oil from its copious foliage is unsurpassed, and not equalled by any 
other tree; 1,000 lb. of fresh leaves with the twigs yield 120 oz. of pure 
volatile oil. Others of this family reach to 500 oz. of oil. ‘These trees have 
been planted at the Cape of Good Hope, and they have completely changed the 
climatic condition of the unhealthy parts of that eolony. It is now a well- 
known fact that trees planted in some insalubrious parts have improved the 
atmosphere, and ague and malarial fevers have become less prevalent, and that 
some places have become healthy after grass had been planted and got to grow. 
Our swamps produce abundance of vegetation, which may account for their 
non-malarious nature. Supposing that, owing to some peculiar circumstances, 
these swamps lost their coating of vegetation, an unhealthy atmosphere would 
most likely be generated, and malarious fevers be produced. 
As we increase’ in population, and. agriculture advances, some tree 
slaughter must take place to make room for crops, but if we keep on as we 
are going many interesting species will become extinct, and all our valuable: 
timbers will be gone before cultivation has extended sufliciently to compensate 
for the absence of the uncultivated plants. We know that this is in direct 
contravention of Nature’s laws, and equally so of human laws. This cutting 
down has in some countries been already carried too far. Whole districts have 
become arid, and droughts are frequent. So it is with us: our forest trees are 
gradually diminishing, and we are in most cases the direct cause of the 
diminution. Picture this colony without trees; it would then become arid and 
unfit for usto live in. Man’s own acts have already made uninhabitable vast 
tracts that once were celebrated for their fertility. The Island of Mauritius 
was a resort for inyalids in quest of health thirty years ago. It was known as 
the “Pearl” of the Indian Ocean, at that time a mass of verdure.. Now, 
through the advance of agriculture, this has all changed. The trees are cleared. 
away, and the ground is converted into sugar plantations. ‘The consequence is 
a diminished amount of rainfall and an increased amount of dryness. With 
proportionate elevation of temperature, the ground has become a hard crust, 
split up into numerous cracks and crevices, and, under the tropical sun, 
noxious exhalations are given off. As moisture was no longer retained by the 
leaves (the trees being absent) and branches, and as the rootlets were no 
longer present to absorb the water, the sources of riyers and streams dried up, 
and now persons are attacked with a malignant fever, and die in a few days. 
Cannot we in this colony take this for a lesson, and consider the. benefits we 
derive from the numerous trees surrounding us? And when we cut down a 
vree, let _us consider well whether it can be spared, remembering that what we 
can cut down in a few hours has taken perhaps hundred of years to grow. 
