"When did he leave?"
"Well, he got drunk and stayed drunk during the holidays, and I had to discharge him. He was a very valuable man when he was sober; but he began to be so erratic in his habits that I was afraid he would make a ghastly mistake some time, so I discharged him before it was too late."
"Are you sure you discharged him before it was too late?"
The druggist looked at the doctor, whom he knew well, and said, "I never heard of any mistake, if he did make it."
"You keep a book, of course, of all the prescriptions sent out?"
"Certainly."
"May we look at that book?"
"I shall be very glad to show it to you. What month or week?"
"I want to see what time you sent this box of morphia to me."
"You don't know about what time it was, do you?