Indeed, the only sound rule about books is that adopted by the man who was asked by a friend to lend him a certain volume.  “I’m sorry,” he said, “but I can’t.”  “Haven’t you got it?” asked the other.  “Yes, I’ve got it,” he said, “but I make it a rule never to lend books.  You see, nobody ever returns them.  I know it is so from my own experience.  Here, come with me.”  And he led the way to his library.  “There,” said he, “four thousand volumes.  Every—­one—­of—­’em—­borrowed.”  No, never lend books.  You can’t trust your dearest friend there.  I know.  Where is that Gil Blas gone?  Eh?  And that Silvio Pellico?  And....  But why continue the list....  He knows.  HE KNOWS.

And hats.  There are people who will exchange hats.  Now that is unpardonable.  That goes outside that dim borderland of conscience where honesty and dishonesty dissemble.  No one can put a strange hat on without being aware of the fact.  Yet it is done.  I once hung a silk hat up in the smoking-room of the House of Commons.  When I wanted it, it was gone.  And there was no silk hat left in its place.  I had to go out bareheaded through Palace Yard and Whitehall to buy another.  I have often wondered who was the gentleman who put my hat on and carried his own in his hand.  Was he a Tory?  Was he a Radical?  It can’t have been a Labour man, for no Labour man could put a silk hat on in a moment of abstraction.  The thing would scorch his brow.  Fancy Will Crooks in a silk hat!  One would as soon dare to play with the fancy of the Archbishop of Canterbury in a bowler—­a thought which seems almost impious.  It is possible, of course, that the gentleman who took my silk umbrella did really make a mistake.  Perhaps if he knew the owner he would return it with his compliments.  The thing has been done.  Let me give an illustration.  I have myself exchanged umbrellas—­often.  I hope I have done it honestly, but one can never be quite sure.  Indeed, now I come to think of it, that silk umbrella itself was not mine.  It was one of a long series of exchanges in which I had sometimes gained and sometimes lost.  My most memorable exchange was at a rich man’s house where I had been invited to dine with some politicians.  It was summer-time, and the weather being dry I had not occasion for some days afterwards to carry an umbrella.  Then one day a sensation reigned in our household.  There had been discovered in the umbrella-stand an umbrella with a gold band and a gold tassle, and the name of a certain statesman engraved upon it.  There had never been such a super-umbrella in our house before.  Before its golden splendours we were at once humbled and terrified—­humbled by its magnificence, terrified by its presence.  I felt as though I had been caught in the act of stealing the British Empire.  I wrote a hasty letter to the owner, told him I admired his politics, but had never hoped to steal his umbrella; then hailed a cab, and took the umbrella and the note to the nearest dispatch office.