As he stumbled on over the creeper-covered ground, the doctor had many a narrow escape from falling, and he could not help envying the ease with which his guide passed the various obstacles around them. The chief thought that occupied the doctor's mind, though, was that which related to the drugging of the party's food that evening. The Malay had mentioned what drug was to be used, namely _toobah_, a vegetable production--in fact the root of a plant which the doctor knew that the Malays used to throw in the pools of the rivers and streams, with the effect that the fish were helplessly intoxicated, and swam or floated on the surface of the water. This plant he had several times tried to obtain and examine, while he made experiments upon its power; but so far he had been unsuccessful. Would it have the same effect upon the human organisation that it had upon a fish? That was the question he had to solve in his mind; but no matter how he turned the subject over, he could extract not the smallest grain of comfort. The only hope he could derive from his thoughts was that the English discipline, with its regular setting of sentries and watchfulness, might be sufficient to defeat the enemy's machinations, and a sufficiency of the officers and men be unaffected by the poison to make a brave stand until the rest had recovered. That might happen; and slightly roused in spirit by this hope, he kept steadily on. One thing was fixed in his own mind, and that was that it was his duty to get back to his party, either to fight with them, to help the wounded, or to share their fate. "Not that I want to die," muttered the doctor. "There's that collection of butterflies unpinned; no one but me could set up all those birds, or understand the numbering; and then there's that boa-constrictor wants dressing over; and worse than all, I've killed my first tiger, and have not saved its skin." "Humph!" he exclaimed directly after, "it seems as if I am to have a hard job to save my own skin." Just then the Malay reeled, and caught at a tree they were passing, when the doctor had only just time to catch him and save him from a heavy fall. Laying his gun aside, he eased the poor fellow down upon the tangled grass, trickling a few more drops from his flask between his lips, and then giving the flask a bit of a shake to hear how much there was left. "Better now," said the Malay, trying to rise. "The trees run round." "Yes, of course they do to you," said the doctor. "Lie still for a while, my good fellow. Is there any water near here?" "Little way on," said the Malay, pointing. "Listen!"