Ether.
The action of sulphuric acid on spirit of wine is alluded to in the works of Raymond Lully in the thirteenth century, and in those attributed to Basil Valentine, by whom the product is described as "an agreeable essence and of good odour." Valerius Cordus, in 1517, described a liquor which he called Oleum Vitrioli Dulce in his "Chemical Pharmacopœia." This was intended to represent the Spiritus Vitrioli Antepilepticus Paracelsi. It was prepared by distilling a mixture of equal parts of sulphuric acid and spirit of wine, after this mixture had been digested in hot ashes for two months. Probably the product obtained by Cordus was what came to be called later the sweet oil of wine, and not what we know as sulphuric ether.
The first ether made for medicinal purposes was manufactured in the laboratory directed by Robert Boyle, and it is said that he and Sir Isaac Newton made some experiments with it at the time. A paper describing his ether investigations was published by Newton in the "Philosophical Transactions" for May, 1700. In 1700 a paper on ether was published by Dr. Frobenius in the "Philosophical Transactions," and in the same publication in 1741 a further paper appeared giving the process by which Frobenius had prepared his "Spiritus Vini Ethereus." Equal parts of oil of vitriol and highly rectified spirit of wine by weight were distilled until a dense liquid began to pass; the retort was then cooled, half the original weight of spirit was added, and the distillation again renewed. This process was repeated as long as ether was produced. Frobenius had been associated with Ambrose Godfrey in Boyle's laboratory, and Godfrey had been supplying ether for some years,
