■ As regards the number of times the incisions can be reopened, 
no definite figure can be given. In some cases, where after io times 
reopening, the incisions still flow freely, it would be irrational to 
stop. One taps as long as possible, but after the 15th reopening it 
is better to stop as the incisions become too broad and require a 
considerable time to thoroughly close again. 
In fixed circumstances, it is possible to continue tapping longer 
than otherwise. 
Temperature and degrees of moisture of the soil may be well 
considered as the principal factors which influence this. 
It may be mentioned that it is not exactly necessary to provide 
the tin cup with a lip with which to fasten it to the trunk. The 
experienced worker can fix the cup into the bark of the tree with 
its sharp edge in such a manner that it will not fall down and like- 
wise is not absolutely necessary to connect the cup and the bark 
with clay. 
In order to prevent coagulation of the latex in the cups and on 
its way into them, it is advisable to put in them some .water before- 
hand and to put a cup for every two incisions. 
If only one cup is used for each vertical row of incisions, the latex 
flowing from the uppermost incision must traverse too long a way 
before it settles in the cup. 
In this way the latex is subject to evaporation, through which is 
caused a bigger yield of scrap rubber (that is the product which is 
coagulated on the stem). 
The method of preparation used in our experiments (coagulating 
with alcohol, drying in air and over unslaked lime) is not sufficiently 
satisfactory to be used tin a large scale. 
Therefore, other experiments were made about which will be 
reported at a suitable time. 
THE HISTORY AND DEVELOPMENT OF 
AGRICULTURE IN THE MALAY 
PENINSULA. 
The history of agriculture in any country and the origin of the 
plants cultivated there is always an instructive and interesting study. 
It is often difficult to determine when or how a plant of economic 
value first found its way into a country and who it was that brought 
or introduced it. In the history of agriculture in the Malay Penin- 
sula the stories of the origin of the introduction of the most valuable 
of our cultivated plants, though more or less known to few, are not 
in accessible records, and many erroneous ideas have been pro- 
mulgated as to the persons and establishments wffio should rightly 
be credited with work the results of which have been of so much 
importance to the country, and which have so much benefited all 
who make even a temporary Tiome in this region. 
