u get the message I sent you about Letter Number Seven?" she
asked.

"Hello, Milly," greeted the presiding genius, pleasantly. "Just what was
that about Number Seven?"

"It isn't getting results."

"No? Let's see it." Dr. Surtaine was as interested in this as he had
been casual about the drug alteration.

"I don't think it's personal enough," pursued the girl, handing him a
sheet of imitation typewriter print.

"Oh, you don't," said her employer, amused. "Maybe you could better it."

"I have," said the girl calmly. "You always tell us to make
suggestions. Mine are on the back of the paper."

"Good for you! Hal, here's the prettiest girl in the shop, and about the
smartest. Milly, this is my boy."

The girl looked up at Hal with a smile and brightened color. He was
suddenly interested and appreciative to see to what a vivid prettiness
her face was lighted by the raised glance of her swift, gray-green eyes.

"Are you coming into the business, Mr. Surtaine?" she asked composedly,
and with almost as proprietary an air as if she had said "our business."

"I don't know. Is it the sort of business you would advise a rather lazy
person to embark in, Miss--"

"Neal," she supplied; adding, with an illustrative glance around, upon
her busy roomful, all sorting and marking correspondence, "You see, I
only give advice by letter."

She turned away to answer one of the subordinates, and, at the same
time, Dr. Surtaine was called aside by a man with a shipping-bill.
Looking down the line of workers, Hal saw that each one was simply
opening, reading, and marking with a single stroke, the letters from a
distributing groove. To her questioner Milly Neal was saying, briskly:

"That's Three and Seven. Can't you see, she says she has spots before
her eyes. That's stomach. And the lameness in the side is kidneys. Mark
it 'Three pass to Seven.' There's a combination form for that."

"What branch of the work is this?" asked Hal, as she lifted her eyes to
his again.

"Symptom correspondence. This is the sorting-room."

"Please explain. I'm a perfect greenhorn, you know."

"You've seen the ads. of course. Nobody could help seeing them. They all
say, 'Write to Professor Certain'--the trade name, you know. It's the
regular stock line, but it does bring in the queries. Here's the
afternoon mail, now."

Hundreds upon hundreds of letters came tumbling from a bag upon the
receiving-table. All were addressed to "Prof." or "Dr." Cer