“It’s only an incident,” continued Dr. Bentley.  “And I am glad of it.  It shows that the young scamp is still in this neighborhood, and that means that there is still a fair chance of his being captured.”

“I wonder why he stole one particular drug from your case?” Dick mused aloud.

Dr. Bentley smiled, not relieving Prescott’s curiosity as to the name of the missing drug.

“It can’t be that Tag means to commit suicide, as a last resort, can it?” Dick suggested.

“I think not,” smiled Dr. Bentley.

Then the leader of Dick & Co. gave up further effort along this line to secure the desired information.

“I started in to offer you a suggestion, Prescott,” continued the medical man.

“Yes, sir; it had something to do with training, I believe.”

“Before I tell you what I have to say, Prescott, suppose you put each of your ‘men’ through the stunts they were doing before.”

“Which one first, sir?”

“Any one of the young men.”

“Dave!” called Dick.

Darrin stepped forward.

“One moment,” said Dr. Bentley.  He felt Dave’s pulse, then nodded. 
“Go ahead, Darrin.”

Dave started in with the work.

“Speed it up!” ordered Dick.  “Faster!  Drive!”

Darry continued at his training work until Dr. Bentley called: 

“Stop!  Now, stand still, young man.”

Bending over, Dr. Bentley placed one ear against Dave’s chest, watch in hand, while the others looked on curiously.

“Just what I thought,” nodded the physician, looking up at last.  “Prescott, you have a lot of bright ideas in training, but you’re driving your squad too hard.  Darrin’s heart doesn’t come down to normal speed as soon as it should.”

“Anything wrong with the heart, sir” asked Darry.

“Nothing.  It’s the trainer that’s wrong,” replied Dr. Bentley.  “It is a fault with a lot of trainers without long experience that they work an athlete’s heart overtime.  Darrin’s heart should have slowed down in a little more than half the time required in this instance.  Set another man at work, Prescott.  I can show you how to do this properly.  Let the others work as hard as Darrin did.  I want data to work on.  Then I’ll lay down a few suggestions that will serve you well.”

This not being interesting to the high school girls, they chatted among themselves.

In the end Dr. Bentley read off some figures he had jotted down, and explained to Prescott what he must regard as a satisfactory heart performance after each bit of training work.

“Now, whenever you don’t bring your work, fairly close to these limits you’ll know that you’re overdoing the training,” Dr. Bentley explained.  “If you overdo on training then you injure the chances of the men of your squad.  The wise trainer keeps within limits.  Keep within such limits, and you’ll find that, bit by bit, your men can endure more and more, and still pass satisfactorily as to diminishing heart speed after stopping grilling.”