and the fumes evolved will pass through the long atap shed 

 mentioned above, in which a number of young plants of Para 

 rubber (Hevea braziliensis) , Rambong (Ficus elastica) and Inga 

 saman {Pithecolobium saman) , grown in pots, are placed at intervals. 

 The ore will be completely calcined and the effect on the plants 

 studied pathologically and otherwise. 



ulphur dioxide. 



I am of opinion that the sulphur dioxide in the fumes from 

 the furnaces working in the various parts of the States causes the 

 greater amount of damage to vegetation, especially at a distance 

 from the furnaces, as it is widelv dispersed by prevailing winds, 

 whereas the arsenious acid would be rapidly condensed after its 

 exit from the furnace chimney. 



To demonstrate the correctness or otherwise of this view 

 attempts are being made to condense the arsenic in the 

 experimental model furnace and allow only the sulphur dioxide to 

 escape. 



The furnace and accessories for carrying out this investi- 

 gation are now complete and the results will be embodied in the 

 report for 1907. 



Laboratory Investigations. 



Owing to the non-equipment of the laboratory in the 

 Institute for Medical Research for agricultural chemical 

 investigations and the lack of apparatus till quite recently, no 

 experiments such as soil or rubber analyses or investigations ot 

 the agricultural produce of this country have so far been 

 undertaken. 



Anti-Opium Drug. 

 Preliminary experiments were carried out with samples of the 

 drug now being distributed in various parts of the States for 

 •curing the opium habit. Samples of the decoction prepared trom 

 the plant used, and a number of specimens of the plant »ere 

 received, when the anti-opium movement first commenced on 

 large SC ale in Kuala Lumpur. The plant is Combretuni 

 sundaicum, a member of the natural order Combretaces, to v i nic 

 family belongs the genus Terminal, some species of which a 

 used for their tanning properties. The drug, which is essential > 

 an extract of the leaves and twigs of the plant, first roasted 

 shallow n-on pans over charcoal fires, and then boiled 

 a definite volume of water and evaporated to a known volume, 

 tound to vary somewhat in composition, and samples 1 



