Popper is a slang term given broadly to drugs of the chemical class called alkyl nitrites that are inhaled. Most widely sold products include the original isoamyl nitrite or isopentyl nitrite, and isopropyl nitrite. Isobutyl nitrite is also widely used but is banned in the European Union. In some countries, poppers are labeled or packaged as room deodorizers, leather polish, nail polish remover, or videotape head cleaner to evade anti-drug laws. Popper use has a relaxation effect on involuntary smooth muscles, such as those in the throat and anus. It is used for practical purposes to facilitate anal sex by increasing blood flow and relaxing sphincter muscles. The drug is also used for recreational drug purposes, typically for the "high" or "rush" that the drug can create, and to enhance sexual pleasure in general. Poppers were part of club culture from the mid-1970s disco scene and returned to popularity in the 1980s and 1990s rave scene. History 19th-century discovery The French chemist Antoine Jérôme Balard synthesized amyl nitrite in 1844. Sir Thomas Lauder Brunton, a Scottish physician born in the year of amyl nitrite's first synthesis, documented its clinical use to treat angina pectoris in 1867 when patients experiencing chest pains would experience complete relief after inhalation. Brunton was inspired by earlier work with the same agent, performed by Arthur Gamgee and Benjamin Ward Richardson. Brunton reasoned that the angina sufferer's pain and discomfort could be reduced by administering amyl nitrite—to dilate the coronary arteries of patients, thus improving blood flow to the heart muscle. Amyl nitrites were originally enclosed in a glass mesh called "pearls". The usual administration of these pearls was done by crushing them between the fingers, followed by a popping sound. This administration process seems to be the origin of the slang term "poppers". It was then administered by direct inhalation of the vapours or inhalation through silk that covered the capsule. Brunton found that amyl nitrites had effects of dilating blood vessels and flushing of the face. Butyl nitrites were also documented around the late 1890s by Brunton and despite being found to have generally the same effects as amyl nitrites, they were never used as a clinical alternative to amyl nitrates. Brunton also found that propyl nitrites had the same effects as well. 20th-century use Although amyl nitrite is known for its practical therapeutic applications, the first documented case of recreational use was in