AGRICULTURAL BULLETIN 



OF THE 



STRAITS 



AND 



FEDERATED MALAY STATES. 



No. 2. J FEBRUARY, 1910. [Vol. IX 



ON THE EFFECT OF ARSENICAL AND SULPHUR FUMES 

 ON VEGETATION, WITH PARTICULAR REFERENCE TO 

 THE PARA RUBBER TREE (HEVEA BRASILIENSIS) 

 AND RAIVIBONG (FICUS ELASTICA.) 



In 1906-07 the question of the supposed deleterious effect of the 

 fumes from the Chinese furnaces, in which low grade tin ores con- 

 taining varying percentages of mispickel (arsenical iron pyrites) 

 were roasted, was acute in one or two planting districts in Selangor, 

 in the Federated Malay States, and numerous complaints were rife as 

 to the injurious effects of the fumes not only on the Para rubber tree 

 but on other forest vegetation, particularly at a certain elevation or 

 height of tree. 



In my agricultural-chemical report for 19D6 (vide Agricultural 

 Bulletin, S. S. and F. M. S., Vol. VI., No. 9, of September, 190;), 

 brief mention was made of experiments then in contemplation to 

 ascertain whether the complaints with reference to the injurious effects 

 of the fumes on the Para rubber trees and on Rambong were justified, 

 and also to ascertain whether such effects, if any, should be attributed 

 to the arsenical or to the sulphurous fumes from these furnaces, since 

 both are produced. 



Method of Roasting. 



A brief description of the method used by the Chinese for 

 roasting these ores might be of interest. 



The furnace consists of a low brick structure, with a fire at one 

 end, the flames from which pass over the ore, which is laid on the bed 

 of the furnace (a reverberatory furnace) and the fumes are carried 

 from thence into a long stack at the other end. The time occupied 



