In due time the tiny heap began to fuse and disappear, but not all of it. In the small burned cavity in the charcoal cake lay a bright pinhead button of metal: light yellow while hot, but cooling to a deeper yellow when the blowing stopped.
During the long summer of prospecting the three apprentice mineralogists had had experience enough in ore testing to know at once that only one metal in the entire list—and only one form of it, at that—could be thus smelted pure from the vein matter in a simple blowpipe flame. Dick was the first to find speech.
“Free gold!” he gasped. And then: “That stuff is disintegrated quartz! Pity’s sake! I ought to have known it at sight. Goodness knows, I’ve seen enough of it in the mineral cabinets at home to know what it looks like.”
Larry was dropping a few drops of strong nitric acid into a test tube while Purdick lighted the alcohol heating lamp. Carefully depositing the tiny globule of metal in the acid, Larry heated the closed end of the tube in the alcohol flame. This was to determine the pureness of the gold. If it were alloyed with silver, the hot acid would immediately dissolve the silver. But there was no chemical reaction visible, and the tiny globule remained apparently undiminished in size; which meant that it was practically all gold.
“It’s the pure quill,” Larry declared, speaking for the first time since the testing began. “Now then, Purdy, where did you find it? That’s the next thing.”
But now Purdick was in despair.
“I can’t tell—can’t remember, to save me. I’m not even sure that I should know the place if I should see it again. I just picked up that bit of stuff as I’ve been picking up hundreds of other bits of rock in the last few weeks, and I don’t know what made me keep it, unless it was the queer, rusty-iron color. I do remember now that I thought it was a bit of iron ore and wondered what it was doing up here among the granites.”
“Well,” said Dick with a grim little smile, “you’ve discovered a gold mine and you’re in the same fix that we all are with the Golden Spider. You had it, and you’ve lost it.”