"That's what's the matter with him," decided Chunky, who had been observing the sick man keenly.
"Guess we drew a prize when we got Juan," announced Walter.
"Give him some medicine, anyway," urged Ned. "He is sick— let him take the dose."
"Let him have the worst you've got in your case, Professor," added Tad, with a laugh.
A grim smile played about the corners of Professor Zepplin's mouth as he ran his fingers over the bottles in his medicine case. Finally, selecting one that seemed to fit the particular ailment of his patient, he directed Chunky to fetch a spoon.
By this time Juan was protesting volubly that he was "all better" and did not need the medicine. The Professor gave no heed to the fellow's protestations.
"Open your mouth," he commanded.
Juan shut his teeth tightly together.
"Open your mouth!" commanded the Professor sternly. "We want no sick men about this camp. It will fix you in a minute."
But the guide steadfastly refused to separate the white teeth.