Edward Gilbert Abbott (1825–1855) was the patient upon whom William T. G. Morton first publicly demonstrated the use of ether as a surgical anesthetic.
 The operation was done in an amphitheater at the Massachusetts General Hospital now known as the Ether Dome on 16 October 1846.
 After Morton administered the ether, surgeon John Collins Warren removed a portion of a tumor from Abbott's neck.
 After Warren had finished, and Abbott regained consciousness, Warren asked the patient how he felt.
 Reportedly, Abbott said, "Feels as if my neck's been scratched."
 Warren then turned to his medical audience and uttered "Gentlemen, this is no Humbug."
 This was presumably a reference to the unsuccessful demonstration of nitrous oxide anesthesia by Horace Wells in the same theater the previous year, which was ended by cries of "Humbug!"
 after the patient groaned with pain.
Diethyl ether, or simply ether, is an organic compound in the ether class with the formula 2O .
 It is a colorless, highly volatile flammable liquid.
 It is commonly used as a solvent in laboratories and as a starting fluid for some engines.
 It was formerly used as a general anesthetic, until non-flammable drugs were developed, such as halothane.
 It has been used as a recreational drug to cause intoxication.
A person with polysubstance dependence is psychologically addicted to being in an intoxicated state without a preference for one particular substance.
 Although any combination of three drugs can be used, studies have shown that alcohol is commonly used with another substance.
 This is supported by one study on polysubstance use that separated participants who used multiple substances into groups based on their preferred drug.
 The three substances were cocaine, alcohol, and heroin, which implies that those three are very popular.
 Other studies have found that opiates, cannabis, amphetamines, hallucinogens, inhalants and benzodiazepines are often used in combination as well.
 The results of a long-term or longitudinal study on substance use led the researchers to observe that excessively using or relying on one drug increased the probability of excessively using or relying on another drug.
Cross-tolerance is a phenomenon that occurs when tolerance to the effects of a certain drug produces tolerance to another drug.
 It often happens between two drugs with similar functions or effects – for example, acting on the same cell receptor or affecting the transmission of certain neurotransmitters.
 Cross-tolerance has been observed with pharmaceutical drugs such as anti-anxiety agents and illicit substances, and sometimes the two of them together.
 Often, a person who uses one drug can be tolerant to a drug that has a completely different function.
 This phenomenon allows one to become tolerant to a drug that they have never even used before.
Poly drug use refers to the use of two or more psychoactive drugs in combination to achieve a particular effect.
 In many cases one drug is used as a base or primary drug, with additional drugs to leaven or compensate for the side effects of the primary drug and make the experience more enjoyable with drug synergy effects, or to supplement for primary drug when supply is low.
Desflurane (1,2,2,2-tetrafluoroethyl difluoromethyl ether) is a highly fluorinated methyl ethyl ether used for maintenance of general anesthesia.
 Like halothane, enflurane, and isoflurane, it is a racemic mixture of ("R") and ("S") optical isomers (enantiomers).
 Together with sevoflurane, it is gradually replacing isoflurane for human use, except in economically undeveloped areas, where its high cost precludes its use.
 It has the most rapid onset and offset of the volatile anesthetic drugs used for general anesthesia due to its low solubility in blood.
By 2013 the drug discovery market had begun shifting from the single to the multi-target paradigm, of which Persomics’ technology is a part.
 Prior to that time, popular drug discovery efforts focused on identifying single drugs that fit into specific cellular targets; this came to be known as target-based screening (i.e. reverse pharmacology).
 The multi-target approach entails the understanding that, although one drug compound might fit into a single target, diseases are associated with complex biological processes, and often multiple cellular targets, which are more difficult to unlock.
 Today phenotypic screening is enjoying a significant resurgence as part of the portfolio of drug discovery strategies leveraged at most companies.
 This is because phenotypic screening products (such as those offered by Persomics) offer a potentially revolutionary approach to discerning multiple cellular targets as the basis for genetic disease.
Ethers ( ) are a class of organic compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups.
 They have the general formula R–O–R′, where R and R′ represent the alkyl or aryl groups.
 Ethers can again be classified into two varieties: if the alkyl groups are the same on both sides of the oxygen atom, then it is a simple or symmetrical ether, whereas if they are different, the ethers are called mixed or unsymmetrical ethers.
 A typical example of the first group is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether" ().
 Ethers are common in organic chemistry and even more prevalent in biochemistry, as they are common linkages in carbohydrates and lignin.
The Ether Dome is a surgical operating amphitheater in the Bulfinch Building at Massachusetts General Hospital in Boston.
 It served as the hospital's operating room from its opening in 1821 until 1867.
 It was the site of the first public demonstration of the use of inhaled ether as a surgical anesthetic on October 16, 1846, otherwise known as Ether Day.
 Crawford Long, a surgeon in Georgia, had previously administered sulfuric ether in 1842, but this went unpublished until 1849.
 The Ether Dome event occurred when William Thomas Green Morton, a local dentist, used ether to anesthetize Edward Gilbert Abbott.
 John Collins Warren, the first dean of Harvard Medical School, then painlessly removed part of a tumor from Abbott's neck.
 After Warren had finished, and Abbott regained consciousness, Warren asked the patient how he felt.
 Reportedly, Abbott said, "Feels as if my neck's been scratched".
 Warren then turned to his medical audience and uttered "Gentlemen, this is no Humbug".
 This was presumably a reference to the unsuccessful demonstration of nitrous oxide anesthesia by Horace Wells in the same theater the previous year, which was ended by cries of "Humbug!"
 after the patient groaned with pain.
The Bulfinch Building of the Massachusetts General Hospital is located on the hospital's main campus on Fruit Street in the West End of Boston, Massachusetts.
 It was designed by architect Charles Bulfinch, and built between 1818 and 1823, with a major expansion in 1844-46.
 A National Historic Landmark, it is an excellent example of Classical Revival architecture, and a rare surviving example of an early 19th-century public hospital building.
 The building is home to the Ether Dome, an operating theater which has been separately designated a National Historic Landmark as the site of the first public demonstration of the use of ether as an anesthetic.

Question: What is one drug that replaced drugs that were first shown to be an anesthetic at the Ether Dome?
Answer: halothane