Returning to Bandjermasin toward the end of October, I began to make arrangements for a journey to Lok Besar, in a hilly region of the Northeast at the source of the Riam Kiwa River. This kampong had recently been visited by the government's mining engineer, Mr. W. Krol, on one of his exploring expeditions. At first glance it might seem unpromising to make researches in a region so near to a stronghold of the Malays, but as he was the first and only European who had been in the upper country of that river, there was a fair chance that the natives might prove of considerable interest. It was a matter of five or six days by prahu from Bandjermasin, followed by a three days' march, and I decided to return by a different route, cross the mountain range, and emerge by Kandangan. Accompanied by Mr. Loing, the surveyor, and the soldier-collector, I started from Bandjermasin on November 1. To travel by the canal to Martapura can hardly be regarded as a pleasure-trip, as mosquitoes and flies are troublesome. Half a year later I went by the road to the same place under more cheerful conditions, and though the day was overcast, the flooded country just north of the town presented a picturesque appearance. Rows of high-gabled Malay houses, with narrow bridges leading out to them, were reflected in the calm water, and beautiful blue morning-glories covered the small bushes growing in the water. Along the road were forests of _melalevca leucodendron,_ of the family of _myrtaceae,_ from which the famous cajuput-oil is obtained. It is a very useful, highly aromatic, and volatile product, chiefly manufactured in the Moluccas, and especially appreciated by the Malays, who employ it internally and externally for all ailments. They are as fond of cajuput-oil as cats are of valeriana. Early in the afternoon the prahus landed us at Martapura, which is renowned for its diamonds and once was the seat of a powerful sultanate. The fields, which have been known for a long time, cover a large area, and the diamonds found in gravel, though mostly small and yellow, include some which are pronounced to be the finest known to the trade. There is always water beneath the surface, and natives in bands of twenty occupy themselves in searching for the precious stones, digging holes that serve besides as self-filling basins in which the gravel is panned. The government does not work the fields. In a factory owned by Arabs the diamonds are cut by primitive but evidently very efficient methods, since South African diamonds are sent here for treatment, because the work can be done much cheaper than in Amsterdam.