Vinyl ether (divinyl ether) is a clear colorless liquid with a characteristic odor. Less dense than water. Vapors heavier than air. Toxic by inhalation. Leake and Chen in 1930 demonstrated that vinyl ether possessed anaesthetic properties, and in 1931 a purer and more stable product was prepared in the research laboratories of Merck and Co. by Ruigh and Major and was used as ananaesthetic on dogs by Knoefel, Guedel, and Leake. These investigators found that dogs were more easily anaesthetized by vinyl ether than by chloroform. They also found that the period of recovery was rapid and free from vomiting; moreover, they did not notice any significant pathological effect on the various organs.The first experiments on human beings were conducted in 1933 by Gelfan and Bell. The first extensive account of vinyl ether anaesthesia in man was published in 1934, when Goldschmidt et al. reported having used it in operations in 461 mixed cases. In all these cases vinyl ether appeared to have no undesirable effect on respiration, the circulation, the liver, or the kidneys. Vinyl ether was widely used in Europe and North America for at least 30 years, until it was replaced by halothane. Vinyl ether was marketed under the name of Vinethine in the United States, Vinesthine in the United Kingdom, and Vinydan in continental Europe. Vinyl ether outlasted many of the inhalation agents introduced in recent years, and served a very useful purpose until safer, non-flammable agents, became available in the mid1960s.