4 
trees grow quite well up to the time tapping is started, and after 
that tliej 7 almost cease putting on girth, even if they are only lightly 
tapped. 
On such trees improvement is a necessity. They are simply 
starved, the bar’k-renewal is bad, and if they do not get some 
nourishment it is only a question of time when the flow of latex will 
cease, if not altogether, then anyhow to such an extent, that the 
profit per acre will be very much reduced, which, of course, is the 
wrong way to go. 
There are thousands of acres with that sort of starved trees 
in the Peninsula. As far as X have seen the south is Ci iderably 
worse than further up country, but there are some every where, and 
T think that something more could he done to resuscitate those trees 
than has hitherto been the case. 
To start manuring on a large scale before it has been properly 
ascertained what the soil is lacking is not wise, and before g’oing 
to such expense it would be the natural thing to try to improve 
matters by cultivation. 
When a young lully plantation on old lalang land has been kept 
perfectly clean for some years big quantities of the top-soil have 
been washed away, leaving the ground hard, and under such 
conditions the trees are unable to get the full benefit from the more 
or less scanty supply of plant food present. 
The chief object of cultivation is to prepare the soil in such a 
way that absorbable plant food can be formed and held until used 
by the plants. 
As a whole, the question of nutriment of plants is very extensive . 
and complicated, and I shall, therefore, on this occasion, confine 
myself to the mentioning of a. few facts. 
It is common knowledge that all plants require, in order to live, 
the following ten elements : oxygen, hydrogen, carbon, nitrogen, 
sulphur, phosphorus, potassium, calcium, iron and magnesium, or 
what is easier to remember, four bases, potash, lime, magnesia and 
iron dioxide and four acids, carbonic acid, sulphuric acid, nitric 
acid and phosphoric acid. 
The plants obtain their supply of carbon chiefly by assimilation 
of carbonic acid through the leaves, and the leguminous and a few 
other kinds of plants are able, aided by bacteria, to assimilate and 
utilize the free nitrogen from the atmosphere, but otherwise all 
plant food is taken from the ground, mostly dissolved in water, hut 
in some instances dissolved by the acid exuded by the young rootlets. 
A small amount of carbonic acid contained in the water is 
assimilated by the roots of plants, but besides this carbonic acid is of 
some use in the ground, mostly by bringing inorganic matter into 
solution . 
