ExpErimEnts and obsErvations on diffErEnt kinds of air The project introduces a canalization of tubes with inhalers connected to N2O gas tanks at some public spaces as the auditorium of a theatre or a metro train. Experiments and observations on different kinds of air refer to a six-volume work published by Joseph Priestley, who was the first to synthesize nitrous oxide. The gas, commonly known as laughing gas, after Humphry Davis who largely experimented the gas on himself and his friends at the Pneumatic Institution in Bristol, was the first anesthetic to be used in surgery. In comparison to the Laughing Gas Chamber of Henrik Plenge Jakobsen, Experiments and observations on different kinds of air refers to the use of the gas at “laughing gas parties” in the early 1800s and the gas has been chosen specifically to reactivate these social contexts. The injection of the gas over the auditorium diffuses it in the space and substitutes the spectacle by the euphorical and hallucinogenic effects of the gas. Its injection in a metro train would relax the commuters and encourage socializing. Experiments and observations on different kinds of air is also a response to the bioethical movement of abolitionism and their project to abolish suffering and make us all happier. The gas generally produces a stuporous, dreamy and sedated feeling in the visitor who remains conscious. The device is rather big and visible contrasting with the invisibility of the gas and the recognizable form of the inhalers enhance a placebo effect. historical references, a demonstration by Joseph Priestley reporting his discoveries and an illustration of a laughing gas party Experiments and observations on different kinds of air, simulation of the project in a theatre and the metro