The Little Black Bag

"The Little Black Bag" is a science fiction short story by American Cyril M. Kornbluth, first published in the July 1950 edition of Astounding Science Fiction. It is a predecessor of sorts to the story "The Marching Morons". It won the 2001 Retroactive Hugo Award for Best Novelette (of 1951) and was also recognized as the 13th best all-time short science fiction story in a 1971 Analog Science Fact & Fiction poll, tied with "Microcosmic God" by Theodore Sturgeon.[1] It was among the stories selected in 1970 by the Science Fiction Writers of America as one of the best science fiction short stories published before the creation of the Nebula Awards. As such, it was published in The Science Fiction Hall of Fame Volume One, 1929-1964.
In the future, humanity has split into a small minority of supergeniuses and those of normal intelligence, and a much larger group of dimwits, as described in "The Marching Morons". The geniuses masquerade as assistants to the morons, the better to covertly manage them and keep them out of trouble.

A "physicist" goads his minder into giving him specifications for a time machine. The faux physicist builds it, and uses it to send a "doctor" friend's highly-automated medical kit into the past (our present), where it is found by Dr. Full, a physician who has succumbed to alcoholism and fallen to the bottom level of society. At first attributing its advanced properties and unfamiliar components to medical advances made since he last practiced, he uses it to heal a seriously injured young child. The patient's cynical eighteen-year-old sister, Angie, discovers the patent application date on one of the instruments (2450) and is quick to grasp the financial opportunities.