“I’d have thought such diseases wouldn’t depend on the time of year.”

“Maybe they don’t, actually,” admitted the other.  “Maybe they’re just crowded out of the public mind by the pressure of other sickness in season, like rheumatism in the early winter, and pneumonia in the late.  But there’s no doubt that the kidney season comes in with the changes of the spring.  That’s one of my discoveries, too.  I tell you, Boyee, I’ve built my success on things like that.  It’s psychology:  that’s what it is.  That’s what you’ve got to learn, if you’re going into the concern.”

“I’m ready, Dad.  It sounds interesting.  More so than I’d have thought.”

“Interesting!  It’s the very heart and core of the trade.”  Dr. Surtaine leaned forward, to tap with an earnest finger on his son’s knee, a picture of expository enthusiasm.  “Here’s the theory.  You see, along about March or April people begin to get slack-nerved and out-of-sortsy.  They don’t know what ails ’em, but they think there’s something.  Well, one look at that ad. sets ’em wondering if it isn’t their kidneys.  After wonder comes worry.  He’s the best little worrier in the trade, Old Lame-Boy is.  He just pesters folks into taking proper care of themselves.  They get Certina, and we get their dollars.  And they get their money’s worth, too,” he added as an afterthought for Hal’s benefit, “for it’s a mighty good thing to have your kidneys tonicked up at this time of year.”

“But, Dad,” queried Hal, with an effort of puzzled reminiscence, “in the old days Certina wasn’t a kidney remedy, was it?”

“Not specially.  It’s always been good for the kidneys.  Good for everything, for that matter.  Besides, the formula’s been changed.”

“Changed?  But the formula’s the vital thing, isn’t it?”

“Yes, yes.  Of course.  Certainly it’s the vital thing:  certainly.  But, you see,—­well,—­new discoveries in medicine and that sort of thing.”

“You’ve put new drugs in?”

“Yes:  I’ve done that.  Buchu, for instance.  That’s supposed to be good for the kidneys.  Dropped some things out, too.  Morphine got sort of a bad name.  The muckrakers did that with their magazine articles.”

“Of course I don’t pretend to know about such things, Dad.  But morphine seems a pretty dangerous thing for people to take indiscriminately.”

“Well, it’s out.  There ain’t a grain of it in Certina to-day.”

“I’m glad of it.”

“Oh, I don’t know.  It’s useful in its place.  For instance, you can’t run a soothing-syrup without it.  But when the Pure Food Law compelled us to print the amount of morphine on the label, I just made up my mind that I’d have no government interference in the Certina business, so I dropped the drug.”

“Did the law hurt our trade much?”

“Not so far as Certina goes.  I’m not even sure it didn’t help.  You see, now we can print ‘Guaranteed under the U.S.  Food and Drugs Act’ on every bottle.  In fact we’re required to.”