"Yes, it isn't exactly perfumed," said Jack. "But how did such a place come there?"
"It's one of those mud-springs of hot water that are found in several places throughout the West," said the scientist. "It must have been quiescent for some time and then the thin skin of alkaline earth formed over it. In Europe, or if we had that spring near a large city, it would be possible to make a fortune with it."
"In what way?" asked Dick.
"As a curative bath," replied the professor. "Every year people spend fortunes to go to Europe and take just such baths."
"Reckon I'd go without washin' then," commented Zeb.
"I'd just as soon bathe in rotten eggs," said Dick.
"Well," said Jack, "I guess we've got off about all the mud we can for the present. We'd better be getting back. It's mighty fortunate that we came in time."
"Yes, I was slipping into the stuff all the time," said the professor. "If I'd been alone on the island I might have never been seen again," he added in quite a matter-of-fact tone. "It's too bad I lost that bag of fossils, though. I had some fine specimens."
"Goodness, no wonder you sank down!" exclaimed Jack. "Why didn't you let go of them?"
The scientist was mildly surprised.