He took a very strong magnifying glass from his table drawer and studied the mixture for nearly half a minute.
As he put the glass down, a satisfied smile flickered across his strong face.
“There is just one more test,” he muttered. “Although I believe it is superfluous. However, here goes.”
He put the tuft of grass to his tongue.
“I knew it,” was his soft exclamation. “Salt! It could not be anything else.”
He pressed a push button at the side of his table, and then unfastened the door of the room. As he returned to his seat, he puffed contentedly at his cigar, still regarding the mud and tuft of grass on the white paper.
“Want me, chief?”
A young fellow, with the bright, alert expression on his rather thin features that tells of an active brain, stood in the doorway.
“Yes, Patsy! Close the door and come over here.”
The young man obeyed, and Nick Carter pointed to the stuff on the paper on his table.