For some minutes he could see nothing. Then, all at once, they saw him raise the gun to his shoulder, take a quick aim and fire, when the horses started, and would have dashed off back, but for the fact that they were arrested by the way being blocked by the baggage animals and Mr Burne.

As the gun was fired its report was magnified a hundredfold, and went rolling along in a series of peals like thunder, while the faint blue smoke rose over where Yussuf stood leaning forward and gazing at some broken stones.

Then all at once he raised the gun again as if to fire, but lowered it with a smile, and walked forward to spurn something with his foot, and upon Lawrence reaching him it was to find him turning over a black-looking serpent of about six feet long, with a short thin tail, the body of the reptile being very thick in proportion to its length. Upon turning it over the Muslim pointed out that it had a peculiar reddish throat, and he declared it to be of a very poisonous kind.

“How do you know it to be poisonous?” said Mr Preston, who had, unseen by them, risen from where he had been thrown.

“Oh, Mr Preston, are you much hurt?” cried Lawrence.

“I must say I am hurt,” said the professor smiling. “A heavy man like me cannot fall from his horse and strike his head against the stones without suffering. But there, it is nothing serious. How do you know that is a poisonous snake, Yussuf?”

“I have been told of people being bitten by them, effendi, and some have died; but I should have said that it was dangerous as soon as I saw the horse shrink from it. Animals do not generally show such horror unless they know that there is danger.”

“I don’t think you are right about the horses,” said the professor quietly, “for they are terrible cowards in their way; but I think you are right about the snake. Serpents that are formed like this, with the thick, sluggish-looking shape, and that peculiar short tail, are mostly venomous. Well, this one will do no more mischief, Burne.”

“No. Nasty brute!” said the old lawyer, gazing down at the reptile after coaxing his horse forward. “What are you going to do, Yussuf?”

“Make sure that it will not bite any of the faithful,” said the guide slowly; and drawing his knife he thrust the reptile into a convenient position, and, after cutting off its head, tossed the still writhing body to the side of the ravine.