"It is sometimes called by that name. It is caused by decaying vegetable matter, and exhibits itself in the form of gases of phosphorus, which appears to burn, but does not, like the vapor which is produced by rubbing certain matches in the dark."
"But how do you account for the disappearance after we shot?"
"I thought they might have disappeared naturally, after you fired, and, therefore, said it might have been a mere coincidence."
This explanation was not a satisfying one for the boys, and the Professor did not place much faith in it, for the following reasons:
"I believe it is our duty now to keep watches during the night, which we can do by turns, so that the sentinel will quietly awaken the next one in his turn, or both in the event of any unusual happening; and furthermore, we should make an early start in the morning."
George was the first watch, and, by agreement, Harry was to be the next, in two hours, for the second period. Before that time passed Baby was very restless, and George tried to soothe him; but before long he began crying. A lusty orang, however small, in a still night, makes an awfully loud noise. The boys never heard anything as loud and as frightful as that cry appeared to them.
All were awake, of course, but the Baby refused to be quieted for fully a quarter of an hour.
"Don't you think Baby's cries will direct the savages to us?"
"It is not at all likely. The savages have no doubt heard the cries many times. It is your imagination which is playing you tricks. Do you suppose the savages know we are here and have a captive orang?"
During the rest of the night they took sleep in snatches, and morning was long in coming. Harry had busied himself in getting a hasty breakfast while the others slept, and Baby was up leaping around nervously, and springing from branch to branch on the adjacent trees.