"Bah!" cried Frank.

"What does _Baa_! mean?" said the professor. "Black sheep?"

"Nonsense! Ask Morris if it would not be as easy as easy to tinge one's skin to any depth, from a soft brown to black."

"Won't do," said the professor. "You'd dye your face, neck, and arms, and some time or other you'd be caught bathing."

"Not much chance for bathing out there when we were away from the Nile, eh?"

"Well, having a sand-bath; and then they'd see that the rest of your skin was white."

"Oh, no, they wouldn't," cried Frank. "I should do as that amateur did who wanted to play Oth.e.l.lo properly--black myself all over."

The professor took off his fez, laid it upon his knees, and with both hands gave his s.h.a.ggy hair a vicious rub, which, however, did not disorder it in the least, seeing that it was as rough as could be before.

"Yes," said the doctor; "he has an answer for all objections, Fred, old fellow."

"Yes, yes, yes," cried the professor, putting on his fez again, and making a vicious dab at the ta.s.sel, which was tickling his neck, but subsided quietly between his shoulders after it had done swinging. "He has something to say to everything. Too much talk. It wouldn't do.

The Baggara are as keen as their swords: they'd see through it directly."

"Then I'd dye it blacker," said Frank.

"Oh, the colour would be right enough, boy," cried the professor, "but that's what would let the cat out of the bag."

"What do you mean?"

"That tongue of yours, my lad. Your speech would betray you directly."

"Oh, no, it would not," said Frank. "Mutes are common enough in the East, are they not?"

"Oh, yes, but--"

"Well, I would not talk."

"Pooh!" cried the professor contemptuously. "You wouldn't talk? Why, you've got a tongue as long as a girl's. You not talk? Why, you'd be sure to burst out with something in plain English just when our lives were depending upon your silence."

"_Urrr_!" growled the young fellow angrily. "Give me credit for a little more common-sense. Do you think, with the success of our expedition and poor Hal's life and happiness at stake, I couldn't make a vow to preserve silence for so many months, and keep it?"

"I do think so," said the professor, clapping one hand down upon the other. "You would find it impossible. What do you say, Bob?"

"Humph!" grunted the doctor.

"Come, there's no need for you to hold your tongue," cried the professor petulantly. "Say something."

"Very well, I'll say something," replied the doctor: "I don't know."

"Yes, you do. You know it's impossible."

"No," said the doctor thoughtfully; "I know it would be very hard, but seeing what a stubborn, determined fellow Frank is, I should not be surprised if he succeeded."

"Hurrah!" cried Frank. "There, Landon."

"Bob ought to know better," cried the professor. "It's impossible-- that's impossible--the whole business is impossible. Can't be done."

"Well, I don't know," said the doctor, taking both hands to his beard and stroking and spreading it out over his breast, where it lay in crisp curls, glistening with many lights and giving him a very n.o.ble and venerable aspect. "I'm beginning to like that idea of going as a learned physician."

"Oh, yes, that's right enough," said the professor. "There's no imposition there. The Arabs would have nothing to find out, and their suspicions would be allayed at once. Then, too, you could humbug them grandly with a few of your modern doctors' tools--one of those double-barrelled stethoscopes, for instance; or a clinical thermometer."

"To be sure," cried Frank. "Modern Magic--good medicine for the unbelieving savages. An electric battery, too; and look here, both of you: the Rontgen rays."

"Ha, ha!" laughed the doctor, and making his beard wag with enjoyment.

"Yes, that would startle them. White man's magic. Fancy, Fred, old chap, a wounded man with a bullet in him, and I at work with my black slave, Frank, here, to help me, in a dark tent, while I made the poor wretch transparent to find out where the bullet lay."

"Yes, or broken spear-head," said the professor eagerly. "I say, Bob, there'd be no gammon over that: the savage beggars would believe that they had a real live magician come amongst them then."

"Yes, ha, ha! wouldn't they? I say, old fellow, I'm beginning to think it ought to be worked."

"Worked, yes," cried Frank excitedly. "I could take a few odds and ends from my laboratory, too, so as to show them some beautiful experiments-- fire burning under water, throwing pota.s.sium on the river to make it blaze; use some phosph.o.r.escent oil; and startle them with Lycopodium dust in the air; or a little fulminating mercury or silver."

"H'm, yes, you might," said the professor thoughtfully. "You could both of you astonish them pretty well, and all that would keep up your character."

"But of course it's all impossible, isn't it?" said Frank, smiling.

"H'm! I don't quite know," said the professor slowly.

"Look here," said the doctor rising, to seat himself upon one end of the hearthrug, where he began trying to drag his legs across into a comfortable sitting position, but failed dismally; "I'm afraid I should never manage this part of the business. My joints have grown too stiff."

"Oh, nonsense," said the professor sharply; "it only wants a little practice. Look here."

He plumped himself down upon the other end of the hearthrug quite in the native manner, and seemed perfectly at his ease, while Frank sat watching them both with his eyes twinkling in his delight.

"You can't do it in those tight trousers. You want good loose, baggy breeches, knickerbockery sort of things. Oh, you'd soon do it.--That's better."

"Yes," said the doctor dubiously; "that's a little better; but these trousers are, as you say, too tight. I tell you what I'd do, Frank," he continued, perfectly seriously, "I'd have my head shaved clean, and keep it so."

"Bravo!" cried the professor excitedly. "Splendid! Your bald head over that grand beard and a very large white turban of the finest Eastern muslin, twisted up as I could twist it for you, would give just the finishing touches. Just spread the skirts of that dressing-gown a little."

Frank sprang to the task, and in arranging the folds uncovered one of the yellow Morocco slippers the doctor happened to be wearing.

"That's good," cried the professor excitedly. "Fetch those sofa cushions, Frank, and put them so that he can rest his arm upon them.

Good! Now a pipe. Here, fish out my stick from under the table.

That's right," he continued, as Frank placed the stick upside down in the doctor's hand, with the ferrule near his lips and the hook resting on the floor, turned up like a bowl.

"Well, I am!" cried the professor, drawing his legs more under him, and nodding at his old school-fellow seated opposite at the other end of the hearthrug. "Franky, boy, he looks the very perfection of a Turkish doctor now, while with the real things on and his head shaved, and the turban--Oh, I haven't a doubt of it, he'd humbug the Mahdi himself if he were alive. I haven't a bit of fear about him. Sit still, old man.--As for myself, I should be all right; when I get out there I feel more of a native than an Englishman. It's you who are the trouble, Franky, for I confess I am coming round."

"I shall get myself up perfectly. You may depend upon that," said the lad confidently, "and all through the voyage out Morris will coach me up about bandaging and helping him in ambulance work, so that I may get to be a bit clever as his a.s.sistant."

"Yes, yes, yes, that's all right," said the professor impatiently.