It was a case for a detective.
And that detective was forthcoming in the person of Auld Reikie, as his messmates frequently called the honest doctor.
"I have it, Sturdy, I have it," he cried one forenoon, rushing into the ward-room. "Man, there is nothing in a' the warld to beat the glorious licht o' science."
"Well, heave round," said Sturdy, lighting a cigar; "show your glorious 'licht,' as you call it."
"I'll do that, man. Listen, Sturdy; listen, my Lord Tomfoozle, for I'll mak the truth apparent to even your feckless noddle."
"Thank you, Reikie," drawled Fitzgerald.
"Every day, then, the siphon is carried away full. You've only to put your thumb on it and the thing's done. Watch the morn, Sturdy, and you'll put your thumb on the culprits."
And Auld Reikie was right.
But the trick was so simple and yet so clever that the culprits were allowed to escape with only a nominal punishment.
* * * * *