The electricity and telephone service had been restored by the time the boys got back. Dr. Miller told them that he had phoned the tenant farmer and arranged for the man to do a little inquiring in the town.
Rick displayed the bag. "Got a specimen," he told the group. He explained their interest in the bag and asked Dr. Miller if he could identify the contents.
The scientist examined the grayish powder from the bag. "It could be any one of a hundred things," he said. "Let's see what we can find out about it."
The farmhouse wasn't equipped for any kind of chemical analysis, but the scientist did what was possible. He tried to dissolve the powder in water, and failed. He tried vinegar, as the only acid available, and failed. He tried ammonia, and failed.
Finally he said, "Well, it isn't cement, and it isn't fertilizer. It's an inorganic substance. I suggest the microscope, Rick. It will at least give us a clue to its structure, if not its identity."
Rick spread a small amount on a slide, switched on the substage light, and put the slide on the stage. He focused, using his highest-power lens combination which gave a magnification of three hundred times.
The powder was clearly crystalline, a mineral of some kind. Rick couldn't identify it. He turned the eyepiece over to Dr. Miller. The scientist had no better luck.
Barby asked, "Could it be an explosive?"
"No, Barby. This is powdered rock of some kind," Dr. Miller answered, his eye at the instrument. "But why anyone should use powdered rock and then hide the bags certainly escapes me. I can't imagine what the powder is for. It isn't a powdered limestone, which might be used on the fields. The crystal structure is wrong for that."
"Wish we had a geologist with us," Rick said. "This calls for an expert." He stared helplessly at the microscope. There was only one more test that could be made, and he saw no use in making it.