109 



Miscellaneous. 



ADVICE ON PLANTING MATTERS. 



A good deal of work which cannot be detailed in a report has been 

 done in the direction of advising Government as to letting of land, schemes 

 for drainage and roads in planting districts, and other matters in which Govern- 

 ment can help the quickly growing rubber industry. Numerous letters of enquiry 

 as to prospects of rubber show that capitalists in England are beginning to 

 be aware ot an agricultural industry which promises considerable profit. The 

 planting community have used the department as a bureau of advice both by 

 correspondence and by personal interviews : by this means the knowledge gained 

 both by the failures and successes of the planter is obtained and recorded, and 

 the department is kept in touch with the progress of planting. 



FUMES FROM TIN ORE FURNACES, 



A matter which has been occupying the attention of the Department 

 of Mines and myself has been the deleterious effects of the fumes caused by 

 roasting of certain tin ores on vegetation and chiefly the injuries caused to 

 cultivated plants. The question has also been considered by the Health Officer 

 in relation to its bearing on the health of men and animals in the vicinity of 

 the furnaces, but that is outside the scope of this report. Some of the ores 

 more recently mined contain large quantities of sulphur and arsenic, and these 

 being driven off in the form of dense white fumes are injurious to a very 

 large number of leaves, Like most poisons in both the animal and vegetable 

 kingdom, these fumes affect different plants variably. Among trees found in 

 the vicinity of furnaces smelting ores with high sulphur and arsenic percentages, 

 the "rain-tree" (Pithecolobhim saman) is by far the most markedly affected. 

 These trees are entirely defoliated, and though, owing to a change in the direction 

 of the wind, new leaves may be able to exist for a short time, they are soon 

 destroyed, and in the course of time this continual defoliation kills the tree. 

 The roots are unaffected and the tree goes on struggling against the destruction 

 of its leaves, The plants which seem least affected by these fumes are the 

 palms, and some of these can be seen growing and retaining their leaves, though 

 not very vigorous, while the neighgbouring Pithecolobium saman and other 

 trees have been killed. In order to gain definite information as to the damage 

 done to cultivated, plants and the conditions necessary to kill the leaves, I have 

 built a model furnace in the grounds of the Medical Institute where the Depart- 

 ment of Agriculture is temporarily housed. Tin ores with a high arsenical 

 percentage will be used in this furnace in the first instance to experiment with 

 plants of Ficus elastica, "Rambong," Hevea brasiliensis, "Para," and other culti- 

 vated plants. Directly sufficient accurate data has been obtained, a simple 

 system of pipes will be placed between the furnace and the chimney, and experiments 

 made as to the cubic space needful to condense the arsenic and sulphur. It may 

 not be necessary to extract all the arseuious acid and sulphur from the fumes, 

 if a sufficient proportion is taken away to render the vapours emitted non-injurious 

 to foliage. 



ERADICATION OF LALANG. 



The question of the most practicable and economical methods of eradicating 

 Imperata arundinaceae, "lalang grass," was one of the first things to occupy 

 my attention, and in July I began a series of experiments as to the value of spraying 

 for destroying this weed. A field near the Laboratory was selected, and part of 

 it divided into seven plots, each l-300th part of an acre. The grass on six of these 

 seven plots, A to P was burnt off ; on the seventh, G, it was " chuukled "— i.e., dug 

 over about 6 inches deep. G, a plot in the centre, was taken as a " control " and not 

 in any way treated, the others were sprayed with varying proportions of copper 



