292 



As regards the number of times the incisions can be reopened, 

 no definite figure can be given. In some cases, where after 10 times 

 reopening, the incisions still flow freely, it would be irrational to 

 stop. One taps as long as possible, but after the 1 5th 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 on 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 who 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 home in this region. 



