He turned up his ledger and ran his finger down the page till he came to the entry of pillow-cases opposite to my ward. And then he laughed a laugh of fiendish glee.

"Do you know," he said, "that instead of having three pillow-cases too few, you've seven too many!"

Such are the traps set by the business man, the expert of ledgers, for the innocent amateur. We had actually got more pillow-cases than we were entitled to. All unwittingly, in my eagerness to placate Sister, I had published the mild chicanery in which she had indulged on behalf of her ward. The sergeant, growing grey in the solution of these abstruse mathematical and psychological mysteries, had suspected this Sister all along. He enlightened me. She had recently been transferred from another ward—and in her going had (against the rules) wafted with her a small selection of that ward's property.... And now there would be a surprise stocktaking in her new ward: the seven surplus pillow-cases—and perhaps other loot—would have to be explained. Sister, in short, was in for a mauvais quart d'heure.

It was a suitable penalty for her crossness. It should have taught her the perils of crossness. With regret I add that she did not envisage the episode in that light. She was merely rather crosser than before. It was without any profound sorrow that I soon afterwards bade her farewell, on her departure to overseas spheres of activity. But she had at least afforded me a lesson in the importance of accuracy over my dirty and clean linen bundles. Never again would I risk the ordeal of a surprise stocktaking; never again would I risk a combat with a ledger-fortified sergeant; never again would I risk any attempt at the tortuous in my dealings with the classifications of the eighty-one items on the tear-off leaf of that dire volume, the Check Book for Hospital Linen.