Mr. Britling Sees it Through by H.G. Wells

After lunch Mr. Britling had a brilliant idea for the ease and comfort of Mr. Direck.

It seemed as though Mr. Direck would be unable to write any letters until his wrist had mended. Teddy tried him with a typewriter, but Mr. Direck was very awkward with his left hand, and then Mr. Britling suddenly remembered a little peculiarity he had which it was possible that Mr. Direck might share unconsciously, and that was his gift of looking-glass writing with his left hand. Mr. Britling had found out quite by chance in his schoolboy days that while his right hand had been laboriously learning to write, his left hand, all unsuspected, had been picking up the same lesson, and that by taking a pencil in his left hand and writing from right to left, without watching what he was writing, and then examining the scrawl in a mirror, he could reproduce his own handwriting in exact reverse. About three people out of five have this often quite unsuspected ability. He demonstrated his gift, and then Miss Cecily Corner, who had dropped in in a casual sort of way to ask about Mr. Direck, tried it, and then Mr. Direck tried it. And they could all do it. And then Teddy brought a sheet of copying carbon, and so Mr. Direck, by using the carbon reversed under his paper, was restored to the world of correspondence again.