fact, it is quite short. It could not be used, for example, in thread, 
bands, or any fine pure gum goods. In solution it loses its tenacity 
very quickly, so that it would not do for high grade cements. 
Another thing about it is that it softens with age, whereas the Para 
rubbers grow hard and oxidize. We think the reasons for these 
differences are two: one being found in the manner of coagulation, 
which does not seem equal to the smoking process ; and the other 
being due to the undoubted change wrought upon the tree by a 
different climate from that in which the tree naturally flourishes. 
It is to be understood, of course, that the rubber is valuable, and 
will find a ready market at a good price, but it is not the equal of 
either fine or coarse Para. We think this is another proof that 
rubber will be cultivated most successfully in the regions where it 
grows wild. 
CORRESPONDENCE. 
To the Editor, 
Agricultural Bulletin. 
Dear Sir, — Reading the notes on the value of Incidental Incre- 
ment of Plant food in Soils in the last issue, i am inclined to add 
the following note on the same subject. There is nothing new 
in it nor am I confident that it deserves publication, 
1 remain, 
Yours sincerely, 
V, K. ME ARON. 
fSth December , /po/. 
Incidental Increment of Plant-food in Soils. 
The rapid decomposition of organic matter in Tropical Soils 
tends to keep the nitrogenous portion of the plant-food in them 
at a minimum, and analysis often shows a comparatively low per- 
centage of nitrogen. But Nature herself, as if to compensate for 
the rapid decomposition of organic nitrogenous matter, has pro- 
vided the Tropics with an increased number of species of Legu- 
minous plants especially of Papilionaceous Sub-order. 1 he roots 
of these plants serve, through the agency of minute organisms 
that live in the roots and the soil, as a medium for rendering 
atmospheric nitrogen available to plants. Though this theory is 
pretty recent the importance which leguminous crops possess as 
valuable fertilizers of soil has long been recognized by farmers, 
both in the East and the West. Hence the invariable rule of 
inserting one or more leguminous crops in a System of Rotation 
of crops. But we are not generally aware of the full importance 
of the part played bv leguminous crops in the incident incre- 
ment of plant-food in soils. Either in forest: plantations, gardens 
or even on waste lands, many of the plants hich are classed as 
weeds are important means of nourishing th soil. Leguminous 
