Is there such thing as "The Gas of Peace" in real life?

In H.G. Wells’ film Things to Come (1936), a world war destroys civilization, and then a techno-scientific elite organization, Wings Over the World (they have airplanes), puts it back together through armed conquest. Being humanitarians, the WOW win their battles by dropping “Gas of Peace” bombs on the enemy – it does not kill them but only knocks them unconscious.

Has anybody ever invented anything like that? That can be safely administered that way on a battlefield, instead of by a highly trained anesthesiologist in an operating room who is being very careful not to kill the patient as these drugs can?

I doubt it. Heck, even actual poison gas does not work very well in battlefield conditions. After the experiences with it in WWI, even the Nazis did not try to use it again.

We’ve had this discussion before several times. The conclusion is there’s no such thing as sleep gas or knock out gas.

What’s that stuff dentists and surgeons use to knock you out, then?

Surgeons don’t knock you out; they wouldn’t know how. That job is left to specialists in the field of anesthesia, either CRNAs (Certified Registered Nurse Anesthetists) or anesthesiologists (MDs qualified to practice anesthesia). This is because, if the situation was not carefully controlled, the chemicals used to knock you out would simply kill you.

Anesthesia is the process of chemically turning off or down some part of your nervous system. There are ways to do that fairly gently now, but there’s no way to make it a one-dose-fits-all job, even if you stipulate that everyone involved will be an adult male in good health.

Recent thread on knock-out gas.

Sorry, I meant something that will work in the open air, such as the OP suggests.

If there was such a thing as safe “sleeping gas”, it would have been used.

The Russians attempted to do that in a hostage situation several years back. They were criticized for that as the hostages were also exposed as part of the plan and many died. the gas used was not disclosed which reportedly cost lives as Dr’s didn’t know how to treat it.

People can be safely anaesthetized one at a time, only. “The Gas of Peace” would be peaceful in that it would kill everyone fairly quickly.

Well, the Nazis found what they considered a better use for poison gas.

Bolding mine.