"Then you think it contained——" began Jack.
"I'm not going to think anything until I finish this experiment," laughed Tom.
He shook the sterilized water about in the bottle, rinsing it well, and the contents he then poured into a test tube. This, after heating, he mixed with some other chemicals.
"Would you mind telling us what you're testing for?" asked Jack.
"Not at all," said Tom quietly. "I'm trying to see if this bottle had any cyanide of potassium in it."
"What! Cyanide?" gasped Bert.
"The stuff that killed the one horse and sickened the others?" asked
Jack.
"That's it. I may find it—I may not."
Tom poured a few drops of another chemical into the test tube. There was a reaction, and at once he uttered a cry:
"There it is!" he fairly shouted. "I'm on the right trail at last!
There was cyanide in the bottle!"