Acetone[1]
IUPAC name 2-Propanone
Systematic name Propan-2-one[2]
Other names Dimethyl ketone[3] β-Ketopropane[3] Propanone[4] 2-Propanone[3] Dimethyl formaldehyde[5]
Identifiers
Abbreviations	DMK
CAS number	67-64-1 Y
PubChem	180
ChemSpider	175 Y
UNII	1364PS73AF Y
EC number	200-662-2
UN number	1090
KEGG	D02311 Y
MeSH	Acetone
ChEBI	CHEBI:15347 Y
ChEMBL	CHEMBL14253 Y
RTECS number	AL3150000
Beilstein Reference	635680
Gmelin Reference	1466
3DMet	B00058
Jmol-3D images	Image 1
SMILES CC(C)=O
InChI InChI=1S/C3H6O/c1-3(2)4/h1-2H3 Y Key: CSCPPACGZOOCGX-UHFFFAOYSA-N Y InChI=1/C3H6O/c1-3(2)4/h1-2H3 Key: CSCPPACGZOOCGX-UHFFFAOYAF
Properties
Molecular formula	C3H6O
Molar mass	58.08 g mol−1
Appearance	Colorless liquid
Odor	Pungent, irritating, floral
Density	0.791 g cm−3[6]
Melting point	-95--93 °C, 178-180 K, -139--136 °F
Boiling point	56-57 °C, 329-330 K, 133-134 °F
log P	-0.042
Vapor pressure	24.46-24.60 kPa (at 20 °C)
Acidity (pKa)	24.2
Basicity (pKb)	-10.2
Refractive index (nD)	1.35900
Viscosity	0.3075 cP
Structure
Coordination geometry	Triagonal planar at C2
Molecular shape	Dihedral at C2
Dipole moment	2.91 D
Thermochemistry
Std enthalpy of formation ΔfHo298	-250.03-(-248.77) kJ mol−1
Std enthalpy of combustion ΔcHo298	-1.772 MJ mol−1
Standard molar entropy So298	200.4 J K−1 mol−1
Specific heat capacity, C	125.45 J K−1 mol−1
Hazards
MSDS	External MSDS
GHS pictograms
GHS signal word	DANGER
GHS hazard statements	H225, H319, H336
GHS precautionary statements	P210, P261, P305+351+338
EU Index	606-001-00-8
EU classification	F Xi
R-phrases	R11, R36, R66, R67
S-phrases	(S2), S9, S16, S26
NFPA 704	3 1 0
Flash point	−17 °C
Autoignition temperature	465 °C
Explosive limits	13.2–57.0%
Threshold Limit Value	1185 mg/m3 (TWA), 2375 mg/m3 (STEL)
LD50	3000 mg/kg (oral, mouse), 20000 mg/kg (dermal, rabbit), LC50 = 19000 mg/m3 (inhalation)
Related compounds
Related compounds	Butanone Isopropanol
Supplementary data page
Structure and properties	n, εr, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Acetone is the organic compound with the formula (CH₃)₂CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.

Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory. About 6.7 million tonnes were produced worldwide in 2010, mainly for use as a solvent and production of methyl methacrylate and bisphenol A.^[7][8] It is a common building block in organic chemistry. Familiar household uses of acetone are as the active ingredient in nail polish remover and as paint thinner.

Acetone is produced and disposed of in the human body through normal metabolic processes. It is normally present in blood and urine. People with diabetes produce it in larger amounts. Reproductive toxicity tests show that it has low potential to cause reproductive problems. Due to the higher energy requirements in pregnant women, nursing mothers and children, they have higher levels of acetone. Ketogenic diets that increase acetone in the body are used to reduce epileptic attacks in infants and children who suffer from recalcitrant refractory epilepsy.

Biosynthesis[link]

This section requires expansion.

Small amounts of acetone are produced in the body by the decarboxylation of ketone bodies. Since it is a byproduct of fermentation, acetone is a byproduct of the distillery industry.

Production[link]

In 2010, the worldwide production capacity for acetone was estimated at 6.7 million tonnes per year.^[9] With 1.56 million tonnes per year, the United States had the highest production capacity,^[10] followed by Taiwan and mainland China. The largest producer of acetone is INEOS Phenol, owning 17% of the world's capacity, with also significant capacity (7-8%) by Mitsui, Sunoco and Shell in 2010.^[9] INEOS Phenol also owns the world's largest production site (420,000 tonnes/annum) in Beveren (Belgium). Spot price of acetone in summer 2011 was 1100-1250 USD/tonne in the United States.^[11]

Current method[link]

Acetone is produced directly or indirectly from propylene. Approximately 83 % of acetone is produced via the cumene process,^[8] as a result, acetone production is tied to phenol production. In the cumene process, benzene is alkylated with propylene to produce cumene, which is oxidized by air to produce phenol and acetone:

Other processes involve the direct oxidation of propylene (Wacker-Hoechst process), or the hydration of propylene to give 2-propanol, which is oxidized to acetone.^[8]

Older methods[link]

Previously, acetone was produced by the dry distillation of acetates, for example calcium acetate in ketonic decarboxylation. During World War I acetone was produced using acetone-butanol-ethanol fermentation with Clostridium acetobutylicum bacteria, which was developed by Chaim Weizmann (later the first president of Israel) in order to help the British war effort.^[8] This acetone-butanol-ethanol fermentation was abandoned due to the small yields.^[8]

Uses[link]

About a third of the world's acetone is used as a solvent, and a quarter is consumed as a precursor to methyl methacrylate.^[7]

Laboratory uses[link]

In the laboratory, acetone is used as a polar, aprotic solvent in a variety of organic reactions, such as S_N2 reactions. The use of acetone solvent is critical for the Jones oxidation. It does not form an azeotrope with water (see azeotrope (data)).^[12] It is a common solvent for rinsing laboratory glassware because of its low cost and volatility. Despite its common use as a supposed drying agent, it is not effective except by bulk displacement and dilution. Acetone can be cooled with dry ice to −78 °C without freezing; acetone/dry ice baths are commonly used to conduct reactions at low temperatures. Acetone is fluorescent under ultraviolet light, and its vapor may be used as a fluorescent tracer in fluid flow experiments.^[13]

Solvent use[link]

Acetone is a good solvent for most plastics and synthetic fibers including those used in laboratory bottles made of polystyrene, polycarbonate and some types of polypropylene.^[14] It is ideal for thinning fiberglass resin, cleaning fiberglass tools and dissolving two-part epoxies and superglue before hardening. It is used as a volatile component of some paints and varnishes. As a heavy-duty degreaser, it is useful in the preparation of metal prior to painting; it also thins polyester resins, vinyl and adhesives. It is also useful for high reliability soldering applications to remove solder rosin after soldering is complete. This helps to prevent the Rusty bolt effect from occurring due to dirty solder contacts.

Many millions of kilograms of acetone are consumed in the production of the solvents methyl isobutyl alcohol and methyl isobutyl ketone. These products arise via an initial aldol condensation to give diacetone alcohol.^[8]

2 (CH₃)₂CO → (CH₃)₂C(OH)CH₂C(O)CH₃

Acetone is used as a solvent by the pharmaceutical industry and as a denaturant in denatured alcohol.^[15] Acetone is also present as an excipient in some pharmaceutical drugs.^[16]

Storage of acetylene[link]

Although itself flammable, acetone is used extensively as a solvent for the safe transporting and storing of acetylene, which cannot be safely pressurized as a pure compound. Vessels containing a porous material are first filled with acetone followed by acetylene, which dissolves into the acetone. One liter of acetone can dissolve around 250 liters of acetylene.^[17][18]

Methyl methacrylate synthesis[link]

Acetone is used to synthesize methyl methacrylate. It begins with the initial conversion of acetone to acetone cyanohydrin:

(CH₃)₂CO + HCN → (CH₃)₂C(OH)CN

In a subsequent step, the nitrile is hydrolyzed to the unsaturated amide, which is esterified:

(CH₃)₂C(OH)CN + CH₃OH → CH₂=(CH₃)CCO₂CH₃ + NH₃

Bisphenol A synthesis[link]

The third major use of acetone (about 20%)^[7] is synthesizing bisphenol A. Bisphenol A is a component of many polymers such as polycarbonates, polyurethanes, and epoxy resins. The synthesis involves the condensation of acetone with phenol:

(CH₃)₂CO + 2 C₆H₅OH → (CH₃)₂C(C₆H₄OH)₂ + H₂O

Medical and cosmetic uses[link]

Acetone is used in a variety of general medical and cosmetic applications and is also listed as a component in food additives and food packaging.

Acetone is commonly used in chemical peeling. Common agents used today for chemical peels are salicylic acid, glycolic acid, 30% salicylic acid in ethanol, and trichloroacetic acid (TCA). Prior to chemexfoliation, the skin is cleaned and excess fat removed in a process called defatting. Acetone, Septisol, or a combination of these agents is commonly used in this process.^{[citation needed]}

Domestic and other niche uses[link]

Acetone is often the primary component in cleaning agents such as nail polish remover. Acetone is a component of superglue remover and easily removes residues from glass and porcelain.

It is used as an artistic agent; when rubbed on the back of a laser print or photocopy placed face-down on another surface and burnished firmly, the toner of the image transfers to the destination surface.

Make-up artists use acetone to remove skin adhesive from the netting of wigs and moustaches by immersing the item in an acetone bath, then removing the softened glue residue with a stiff brush.

Safety[link]

Flammability[link]

The most hazardous property of acetone is its extreme flammability. At temperatures greater than acetone's flash point of −20 °C (−4 °F), air mixtures of between 2.5% and 12.8% acetone, by volume, may explode or cause a flash fire. Vapors can flow along surfaces to distant ignition sources and flash back. Static discharge may also ignite acetone vapors.^[19] It auto-ignites at 465 °C (869 °F).

Acetone peroxide[link]

When oxidized, acetone forms acetone peroxide as a byproduct, which is a highly unstable compound. It may be formed accidentally, e.g. when waste hydrogen peroxide is poured into waste solvent containing acetone. Due to its instability, it is rarely used, despite its easy chemical synthesis.

Health information[link]

Acetone has been studied extensively and is generally recognized to have low acute and chronic toxicity if ingested and/or inhaled. Inhalation of high concentrations (around 9200 ppm) in the air caused irritation of the throat in humans in as little as 5 minutes. Inhalation of concentrations of 1000 ppm caused irritation of the eyes and of the throat in less than 1 hour; however, the inhalation of 500 ppm of acetone in the air caused no symptoms of irritation in humans even after 2 hours of exposure. Acetone is not currently regarded as a carcinogen, a mutagenic chemical or a concern for chronic neurotoxicity effects.^[19]

Acetone can be found as an ingredient in a variety of consumer products ranging from cosmetics to processed and unprocessed foods. Acetone has been rated as a GRAS (Generally Recognized as Safe) substance when present in beverages, baked foods, desserts, and preserves at concentrations ranging from 5 to 8 mg/L. Additionally, a joint U.S-European study found that acetone’s "health hazards are slight."^{[citation needed]}

Toxicology[link]

Acetone is believed to exhibit only slight toxicity in normal use, and there is no strong evidence of chronic health effects if basic precautions are followed.^[20]

At very high vapor concentrations, acetone is irritating and, like many other solvents, may depress the central nervous system. It is also a severe irritant on contact with eyes, and a potential pulmonary aspiration risk. In one documented case, ingestion of a substantial amount of acetone led to systemic toxicity, although the patient eventually fully recovered.^[21] Some sources estimate LD₅₀ for human ingestion at 1.159 g/kg; LD₅₀ inhalation by mice is given as 44 g/m³, over 4 hours.^[22]

Acetone has been shown to have anticonvulsant effects in animal models of epilepsy, in the absence of toxicity, when administered in millimolar concentrations.^[23] It has been hypothesized that the high-fat low-carbohydrate ketogenic diet used clinically to control drug-resistant epilepsy in children works by elevating acetone in the brain.^[23]

• EPA EPCRA Delisting (1995). EPA removed acetone from the list of “toxic chemicals” maintained under Section 313 of the Emergency Planning and Community Right to Know Act (EPCRA). In making that decision, EPA conducted an extensive review of the available toxicity data on acetone and found that acetone "exhibits acute toxicity only at levels that greatly exceed releases and resultant exposures", and further that acetone "exhibits low toxicity in chronic studies".

• Genotoxicity. Acetone has been tested in more than two dozen in vitro and in vivo assays. These studies indicate that acetone is not genotoxic.

• Carcinogenicity. EPA in 1995 concluded, "There is currently no evidence to suggest a concern for carcinogenicity". (EPCRA Review, described in Section 3.3). NTP scientists have recommended against chronic toxicity/carcinogenicity testing of acetone because "the prechronic studies only demonstrated a very mild toxic response at very high doses in rodents".

• Neurotoxicity and Developmental Neurotoxicity. The neurotoxic potential of both acetone and isopropanol, the metabolic precursor of acetone, have been extensively studied. These studies demonstrate that although exposure to high doses of acetone may cause transient central nervous system effects, acetone is not a neurotoxicant. A guideline developmental neurotoxicity study has been conducted with isopropanol, and no developmental neurotoxic effects were identified, even at the highest dose tested. (SIAR, pp. 1, 25, 31).

• Environmental. When the EPA exempted acetone from regulation as a volatile organic compound (VOC) in 1995, EPA stated that this exemption would "contribute to the achievement of several important environmental goals and would support EPA’s pollution prevention efforts". 60 Fed. Reg. 31,634 (June 16, 1995). 60 Fed. Reg. 31,634 (June 16, 1995). EPA noted that acetone could be used as a substitute for several compounds that are listed as hazardous air pollutants (HAP) under section 112 of the Clean Air Act.

Environmental effects[link]

Acetone evaporates rapidly, even from water and soil. Once in the atmosphere, it is degraded by UV light with a 22-day half-life. Acetone dissipates slowly in soil, animals, or waterways since it is sometimes consumed by microorganisms,^[24] but it is a significant groundwater contaminant due to its high solubility in water. The LD₅₀ of acetone for fish is 8.3 g/L of water (or about 0.8%) over 96 hours, and its environmental half-life is about 1 to 10 days. Acetone may pose a significant risk of oxygen depletion in aquatic systems due to the microbial activity consuming it.^[25]

References[link]

External links[link]

• International Chemical Safety Card 0087
• National Pollutant Inventory: Acetone
• NIOSH Pocket Guide to Chemical Hazards
• Hazardous substances databank entry at the national library of medicine
• SIDS Initial Assessment Report for Acetone from the Organisation for Economic Co-operation and Development (OECD)
• Calculation of vapor pressure, liquid density, dynamic liquid viscosity, surface tension of acetone
• Fisher Chemical MSDS

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (October 2009)

The Crystal Method
The Crystal Method performing at SXSW 2009.
Background information
Origin	Los Angeles, California, United States
Genres	Alternative dance, chemical breaks, big beat, breakbeat, EDM
Years active	1993–present
Labels	Outpost, Geffen, V2, Tiny E
Website	TheCrystalMethod.com
Members
Scott Heisler Kirkland Ken B. Jordan

The Crystal Method is an American electronic music duo that was created in Las Vegas, Nevada by Ken Jordan and Scott Kirkland in the early 1990s. The Crystal Method's music has appeared in numerous TV shows, films, video games, and advertisements. Their best-selling album, Vegas, was certified platinum in 2007.

Biography[link]

The Crystal Method is made up of two members, Ken Jordan and Scott Kirkland. Before The Crystal Method was formed, Ken and Scott started working on music while working at the grocery store and while Ken was a local DJ in Las Vegas as well as the college radio program director at UNLV. Ken taught Scott how to DJ, and when Ken moved to L.A. to work for a producer, Scott took over his job DJ'ing at the local club. Scott would follow Ken out to L.A., and they formed The Crystal Method in 1993.

Early days (1993–1995)[link]

By the early '90s, both Ken and Scott had moved from Las Vegas to Los Angeles. Ken Jordan and Scott Kirkland bought a house together, in Glendale, California, which had a small underground shelter beneath the front lawn. Originally intending to turn the shelter into a studio, it proved to be an unrealistic idea and the duo set up a studio in their house (which was located under a Los Angeles Overpass. They subsequently named their studio The Bomb Shelter.The Crystal Method (interview) (1999). Better Living Through Circuitry (Motion picture). United States: Cleopatra Pictures. http://us.imdb.com/title/tt0207998/. 

After The Bomb Shelter was built, a tape of The Crystal Method's music found its way to a British DJ named Justin King. King was interested in starting a record label that would showcase American electronic dance acts. King teamed up with Scottish Steve Melrose to form the record label City of Angels. The first official release from the City of Angels label was The Crystal Method's "Now is the Time". The Crystal Method were signed to Outpost Recordings in 1996.

[edit] Vegas (1996–1998)

After the band signed with Outpost, they began working on their debut album. The group's second (and last) single on City of Angels was "Keep Hope Alive". Their next release was on the Mortal Kombat: More Kombat soundtrack, "Come2gether".

On September 8, 1997, The Crystal Method released their best-selling album, Vegas. Vegas peaked at number 92 on the Billboard 200.^[1] It was certified gold by the RIAA in 1998, then platinum in 2007.^[2]

Five of the album's ten tracks were released as singles: "Trip Like I Do", "Busy Child", "High Roller", "Comin' Back", and "Keep Hope Alive".

[edit] Tweekend (1999–2002)

In 1999, the band went into the studio to record their next studio album, Tweekend, which featured more guest artists than Vegas had. The album was released in July 2001, and peaked at number 32 on the Billboard 200,^[1] which is still the group's highest album chart position.

Featured guests from the album include Rage Against the Machine guitarist Tom Morello, Stone Temple Pilots vocalist Scott Weiland, and others, like Doug Grean, DJ Swamp, Ryan "Ryu" Maginn, and Julie Gallios. Four singles were released from Tweekend: "Wild, Sweet and Cool", "Murder", "Blowout", "Name of the Game".

[edit] Community Service

Jordan and Kirkland used to have a radio show called "Community Service" which aired Friday nights on radio station Indie 103.1, in California.^{[citation needed]} They played electronic music and hosted guests, like Death in Vegas and UNKLE. Their show came back on air in 2011 and airs weekly on Sirius XMs Channel 52.

A year after the release of Tweekend, The Crystal Method released a continuous mix album based on their radio show, titled Community Service. The album does not feature any new studio material from The Crystal Method, but is composed of remixes of bands like P.O.D., Rage Against the Machine, and Garbage, plus remixes of songs from Tweekend. Their remix of P.O.D.'s "Boom" from this album, also appeared in the video game Amplitude.

Community Service peaked at number 160 on the Billboard 200, number five on the Top Electronic Albums chart, and number 15 on the Top Independent Albums chart.^[1]

[edit] Legion of Boom (2003–2005)

After the release of Community Service, The Crystal Method went back into the studio to record their third album, Legion of Boom. During the recording, they used the house as their recording studio instead of The Bomb Shelter.^{[citation needed]}

In December 2003, the single "Born Too Slow", with vocals from John Garcia and guitar by Wes Borland was released. Legion of Boom was released on January 13, 2004, and peaked at number 36 on the Billboard 200.^[1] It sold over 25,000 copies in its first week.^[3] The track was also part of the soundtrack of the very popular racing game Need for Speed: Underground, used prominently especially in its demo.

The other single released from Legion of Boom, "Starting Over", featured vocals from Rahzel from The Roots. No other singles were released but other songs, including "Weapons of Mass Distortion", "Bound Too Long" and "Realizer", appeared in various movies and TV shows. "I Know It's You" appeared in the trailer for the film Resident Evil: Extinction, and includes vocals by the movie's star, Milla Jovovich.

In 2005, the album was nominated for the Best Electronic/Dance Album Grammy,^[4] the first year that category existed. It lost to Kish Kash by Basement Jaxx.^[5]

It is also around this time that Jordan and Kirkland formed their own record label, called Tiny e Recordings.^[3]

[edit] Community Service II

On April 5, 2005, The Crystal Method released their sequel to Community Service, called Community Service II, another continuous mix of electronica songs and remixes of music by artists including The Doors, Unkle, New Order and Smashing Pumpkins. The album peaked at number 31 on the Top Independent Albums chart and number 8 on the Top Electronic albums chart.^[1]

A 5-track EP, Community Service II Exclusives, was also released through the iTunes Store. It included one new track, "Badass", and full versions of four tracks from Community Service II. It was removed from the iTunes store not long after it was released.^[3]

[edit] Drive, London, and Vegas re-release (2006–2008)

The group composed and performed the score for the film London, which was released in February 2006. The soundtrack album included excerpts from the score, two Crystal Method vocal tracks—"Smoked" and "Glass Breaker", which were also released as a single—and songs by artists like Evil Nine, The Out Crowd, and The Perishers.

Shortly after the release of the London soundtrack, The Crystal Method was approached by Nike to take part in a series of music releases specifically designed to be listened to while running. The group's contribution, Drive: Nike + Original Run—the first in the series^[6]—was initially released digitally, in June 2006, with the physical release following a year later. Drive peaked at number 23 on the Top Electronic Albums chart.^[1] The album, a 45 minute continuous mix, starts off slow, increases in tempo, and slows at the end, following the arc of a typical distance run.^[3] In 2006 the track Robogirl released by the duo appeared on Dance Dance Revolution: SuperNOVA as well. ^[7]

In 2007, ten years after its original release, the group's debut album, Vegas was certified platinum by the RIAA.^[2] One month later, a special edition of the album was released, with a second disc including remixes and video.

In late 2008, the group remixed their song "Now Is the Time". Where the original version featured samples of Jesse Jackson, this "Vote '08 Remix" used samples of Barack Obama, marking the presidential election.

[edit] Divided by Night (2009–present)

Following the release of Legion of Boom, The Crystal Method began construction of a new, full-sized recording studio in Los Angeles—Crystalwerks. When it was finished, they began work on their next album, Divided by Night.

On April 14, 2009, The Crystal Method released the digital single "Drown in the Now". A second single, "Black Rainbows", was released via Beatport two weeks later.

The Divided by Night tour started in Boston on May 6, and the album was released the following week. It peaked at number 38 on the Billboard 200, number two on the Top Electronic Albums chart, and number four on the Top Independent Albums chart,^[1] and also granted the duo another Grammy nomination. The album features guest artists including Peter Hook (of New Order), Matisyahu, Meiko, Justin Warfield, Emily Haines (of Metric), and Jason Lytle.

X Games 3D: The Movie, released in August 2009, included a number of Crystal Method songs and remixes,^[8] including "Drown in the Now" and "Now Is the Time".

"Re:Generation Music Project 2012"[link]

The Crystal Method's most recent track "I'm Not Leaving," featured a collaboration with Motown's Martha Reeves for the Re:Generation Music Project documentary. The film followed five DJ/producers who each collaborated with one of five singers, each from a different genre of music.

Instruments[link]

The Crystal Method use a wide array of equipment, with the Clavia Nord Lead being most closely associated with their style and sound. It was the primary source of sound for their first album Vegas.^{[citation needed]}

Discography[link]

• Vegas (1997)
• Tweekend (2001)
• Legion of Boom (2004)
• Divided by Night (2009)

References[link]

External links[link]

• Official website
• The Crystal Method at Allmusic
• The Crystal Method at the Internet Movie Database

Jack the Ripper
"With the Vigilance Committee in the East End: A Suspicious Character" from The Illustrated London News, 13 October 1888
Background information
Birth name	Identity unknown
Also known as	"The Whitechapel Murderer" "Leather Apron"
Killings
Number of victims	5+?
Country	United Kingdom

"Jack the Ripper" is the best-known name given to an unidentified serial killer who was active in the largely impoverished areas in and around the Whitechapel district of London in 1888. The name originated in a letter, written by someone claiming to be the murderer, that was disseminated in the media. The letter is widely believed to have been a hoax, and may have been written by a journalist in a deliberate attempt to heighten interest in the story. Other nicknames used for the killer at the time were "The Whitechapel Murderer" and "Leather Apron".

Attacks ascribed to the Ripper typically involved female prostitutes from the slums whose throats were cut prior to abdominal mutilations. The removal of internal organs from at least three of the victims led to proposals that their killer possessed anatomical or surgical knowledge. Rumours that the murders were connected intensified in September and October 1888, and letters from a writer or writers purporting to be the murderer were received by media outlets and Scotland Yard. The "From Hell" letter, received by George Lusk of the Whitechapel Vigilance Committee, included half of a preserved human kidney, supposedly from one of the victims. Mainly because of the extraordinarily brutal character of the murders, and because of media treatment of the events, the public came increasingly to believe in a single serial killer known as "Jack the Ripper".

Extensive newspaper coverage bestowed widespread and enduring international notoriety on the Ripper. An investigation into a series of brutal killings in Whitechapel up to 1891 was unable to connect all the killings conclusively to the murders of 1888, but the legend of Jack the Ripper solidified. As the murders were never solved, the legends surrounding them became a combination of genuine historical research, folklore, and pseudohistory. The term "ripperology" was coined to describe the study and analysis of the Ripper cases. There are now over one hundred theories about the Ripper's identity, and the murders have inspired multiple works of fiction.

Background[link]

In the mid-19th century, England experienced an influx of Irish immigrants, who swelled the populations of England's major cities, including the East End of London. From 1882, Jewish refugees from Eastern Europe and Tsarist Russia moved into the same area.^[1] The civil parish of Whitechapel in London's East End became increasingly overcrowded. Work and housing conditions worsened, and a significant economic underclass developed.^[2] Robbery, violence and alcohol dependency were commonplace, and the endemic poverty drove many women to prostitution. In October 1888, London's Metropolitan Police Service estimated that there were 1200 prostitutes and about 62 brothels in Whitechapel.^[3] The economic problems were accompanied by a steady rise in social tensions. Between 1886 and 1889, frequent demonstrations, such as that of 13 November 1887, led to police intervention and further public unrest.^[4] Racism, crime, social disturbance, and real deprivation fed public perceptions that Whitechapel was a notorious den of immorality.^[5] In 1888, such perceptions were strengthened when a series of vicious and grotesque murders attributed to "Jack the Ripper" received unprecedented coverage in the media.^[6]

Murders[link]

The sites of the first seven Whitechapel murders – Osborn Street (centre right), George Yard (centre left), Hanbury Street (top), Buck's Row (far right), Berner Street (bottom right), Mitre Square (bottom left), and Dorset Street (middle left)

The large number of attacks against women in the East End during this era adds uncertainty to how many victims were killed by the same person.^[7] Eleven separate murders, stretching from 3 April 1888 to 13 February 1891, were included in a London Metropolitan Police Service investigation, and were known collectively in the police docket as the "Whitechapel murders".^[8][9] Opinions vary as to whether these murders should be linked to the same culprit, but five of the eleven Whitechapel murders, known as the "canonical five", are widely believed to be the work of the Ripper.^[10] Most experts point to deep throat slashes, abdominal and genital-area mutilation, removal of internal organs, and progressive facial mutilations as the distinctive features of Jack the Ripper's modus operandi.^[11] The first two cases in the Whitechapel murders file, those of Emma Elizabeth Smith and Martha Tabram, are not included in the canonical five.^[12]

Smith was robbed and sexually assaulted on Osborn Street, Whitechapel, on 3 April 1888. A blunt object was inserted into her vagina, which ruptured her peritoneum. She developed peritonitis, and died the following day at London Hospital.^[13] She said that she had been attacked by two or three men, one of whom was a teenager.^[14] The attack was linked to the later murders by the press,^[15] but most authors conclude that it was gang violence unrelated to the Ripper case.^[8][16][17]

Tabram was killed on 7 August 1888; she had suffered 39 stab wounds. The savagery of the murder, the lack of obvious motive, and the closeness of the location (George Yard, Whitechapel) and date to those of the later Ripper murders led police to link them.^[18] However, the attack differs from the canonical murders in that Tabram was stabbed rather than slashed at the throat and abdomen. Many experts today do not connect it with the later murders because of the difference in the wound pattern.^[19]

Canonical five[link]

The canonical five Ripper victims are Mary Ann Nichols, Annie Chapman, Elizabeth Stride, Catherine Eddowes and Mary Jane Kelly. Nichols' body was discovered at about 3:40 a.m. on Friday 31 August 1888 in Buck's Row (now Durward Street), Whitechapel. The throat was severed deeply by two cuts, and the lower part of the abdomen was partly ripped open by a deep, jagged wound. Several other incisions on the abdomen were caused by the same knife.^[20]

Chapman's body was discovered at about 6 a.m. on Saturday 8 September 1888 near a doorway in the back yard of 29 Hanbury Street, Spitalfields. As in the case of Mary Ann Nichols, the throat was severed by two cuts.^[21] The abdomen was slashed entirely open, and it was later discovered that the uterus had been removed.^[22] At the inquest, one witness described seeing Chapman at about 5:30 a.m. with a dark-haired man of "shabby-genteel" appearance.^[23]

Stride and Eddowes were killed in the early morning of Sunday 30 September 1888. Stride's body was discovered at about 1 a.m., in Dutfield's Yard, off Berner Street (now Henriques Street) in Whitechapel. The cause of death was one clear-cut incision which severed the main artery on the left side of the neck. Uncertainty about whether Stride's murder should be attributed to the Ripper, or whether he was interrupted during the attack, stems from the absence of mutilations to the abdomen.^[24] Witnesses who thought they saw Stride with a man earlier that night gave differing descriptions: some said her companion was fair, others dark; some said he was shabbily dressed, others well-dressed.^[25] Eddowes' body was found in Mitre Square, in the City of London, three-quarters of an hour after Stride's. The throat was severed, and the abdomen was ripped open by a long, deep, jagged wound. The left kidney and the major part of the uterus had been removed. A local man, Joseph Lawende, had passed through the square with two friends shortly before the murder, and he described seeing a fair-haired man of shabby appearance with a woman who may have been Eddowes.^[26] His companions, however, were unable to confirm his description.^[26] Eddowes' and Stride's murders were later called the "double event".^[27] Part of Eddowes' bloodied apron was found at the entrance to a tenement in Goulston Street, Whitechapel. Some writing on the wall above the apron piece, which became known as the Goulston Street graffito, seemed to implicate a Jew or Jews, but it was unclear whether the graffito was written by the murderer as he dropped the apron piece, or merely incidental.^[28] Police Commissioner Charles Warren feared the graffito might spark antisemitic riots, and ordered it washed away before dawn.^[29]

Official police photograph of Mary Kelly's murder scene in 13 Miller's Court^[8]

Kelly's gruesomely mutilated body was discovered lying on the bed in the single room where she lived at 13 Miller's Court,^[8] off Dorset Street, Spitalfields, at 10:45 a.m. on Friday 9 November 1888. The throat had been severed down to the spine, and the abdomen virtually emptied of its organs. The heart was missing.

The canonical five murders were perpetrated at night, on or close to a weekend, and either at the end of a month or a week or so after.^[30] The mutilations became increasingly severe as the series of murders proceeded, except for that of Stride, whose attacker may have been interrupted.^[31] Nichols was not missing any organs; Chapman's uterus was taken; Eddowes had her uterus and a kidney removed and her face mutilated; Kelly's body was eviscerated and her face hacked away, though only her heart was missing from the crime scene.

Historically, the belief that these five crimes were committed by the same man derives from contemporary documents that link them together to the exclusion of others.^[32] In 1894, Sir Melville Macnaghten, Assistant Chief Constable of the Metropolitan Police Service and Head of the Criminal Investigation Department (CID), wrote a report that stated: "the Whitechapel murderer had 5 victims—& 5 victims only".^[33] Similarly, the canonical five victims were linked together in a letter written by the police surgeon Thomas Bond to Robert Anderson, head of the London CID, on 10 November 1888.^[34] Some researchers have posited that while some of the murders were undoubtedly the work of a single killer, an unknown larger number of killers acting independently were responsible for the others.^[35] Authors Stewart P. Evans and Donald Rumbelow argue that the canonical five is a "Ripper myth" and that while three cases (Nichols, Chapman, and Eddowes) can be definitely linked, there is less certainty over Stride and Kelly, and less again over Tabram.^[36] Conversely, others suppose that the six murders between Tabram and Kelly were the work of a single killer.^[11] Dr Percy Clark, assistant to the examining pathologist George Bagster Phillips, linked only three of the murders and thought the others were perpetrated by "weak-minded individual[s] ... induced to emulate the crime".^[37] Macnaghten did not join the police force until the year after the murders, and his memorandum contains serious factual errors about possible suspects.^[38]

Later Whitechapel murders[link]

Kelly is generally considered to be the Ripper's final victim, and it is assumed that the crimes ended because of the culprit's death, imprisonment, institutionalisation, or emigration.^[16] The Whitechapel murders file does, however, detail another four murders that happened after the canonical five: those of Rose Mylett, Alice McKenzie, the Pinchin Street torso and Frances Coles.

Mylett was found strangled in Clarke's Yard, High Street, Poplar on 20 December 1888. As there was no sign of a struggle, the police believed that she had accidentally choked herself while in a drunken stupor, or committed suicide.^[39] Nevertheless, the inquest jury returned a verdict of murder.^[39]

McKenzie was killed on 17 July 1889 by severance of the left carotid artery. Several minor bruises and cuts were found on the body, discovered in Castle Alley, Whitechapel. One of the examining pathologists, Thomas Bond, believed this to be a Ripper murder, though another pathologist, George Bagster Phillips, who had examined the bodies of three previous victims, disagreed.^[40] Later writers are also divided between those who think that her murderer copied the Ripper's modus operandi to deflect suspicion from himself,^[41] and those that ascribe it to the Ripper.^[42]

"The Pinchin Street torso" was a headless and legless torso of an unidentified woman found under a railway arch in Pinchin Street, Whitechapel, on 10 September 1889. It seems probable that the murder was committed elsewhere and that parts of the dismembered body were dispersed for disposal.^[43]

Coles was killed on 13 February 1891 under a railway arch at Swallow Gardens, Whitechapel. Her throat was cut but the body was not mutilated. James Thomas Sadler, seen earlier with her, was arrested by the police, charged with her murder and was briefly thought to be the Ripper.^[44] He was, however, discharged from court for lack of evidence on 3 March 1891.^[44]

Other alleged victims[link]

In addition to the eleven Whitechapel murders, commentators have linked other attacks to the Ripper. In one case, that of "Fairy Fay", it is unclear whether the attack was real or fabricated as a part of Ripper lore.^[45] "Fairy Fay" was a nickname given to a victim allegedly found on 26 December 1887 "after a stake had been thrust through her abdomen",^[46][47] but there were no recorded murders in Whitechapel at or around Christmas 1887.^[48] "Fairy Fay" could have been created by the press through confusion of the details of the murder of Emma Elizabeth Smith with a separate non-fatal attack the previous Christmas.^[45] Most authors agree that "Fairy Fay" never existed.^[45][49]

Annie Millwood was admitted to Whitechapel workhouse infirmary with stab wounds in the legs and lower abdomen on 25 February 1888.^[50] She was discharged but died from apparently natural causes aged 38 on 31 March 1888.^[49] She was later postulated as the Ripper's first victim, but the attack cannot be linked definitely.^[51] Another supposed early victim was Ada Wilson,^[52] who reportedly survived being stabbed twice in the neck on 28 March 1888.^[53] Annie Farmer, who resided at the same lodging house as Martha Tabram,^[54] reported an attack on 21 November 1888. She had a superficial cut on her throat, but it was possibly self-inflicted.^[55]

"The Whitehall Mystery" of October 1888

"The Whitehall Mystery" was a term coined for the discovery of a headless torso of a woman on 2 October 1888 in the basement of the new Metropolitan Police headquarters being built in Whitehall. An arm belonging to the body was previously discovered floating in the river Thames near Pimlico, and one of the legs was subsequently discovered buried near where the torso was found.^[56] The other limbs and head were never recovered and the body was never identified. The mutilations were similar to those in the Pinchin Street case, where the legs and head were severed but not the arms. The Whitehall Mystery and the Pinchin Street case may have been part of a series of murders, called the "Thames Mysteries", committed by a single serial killer, dubbed the "Torso killer".^[57] Whether Jack the Ripper and the "Torso killer" were the same person or separate serial killers active in the same area is debatable.^[57] As the modus operandi of the Torso killer differed from that of the Ripper, police at the time discounted any connection between the two.^[58] Elizabeth Jackson, a prostitute whose various body parts were collected from the river Thames between 2 and 25 June 1889, may have been another victim of the "Torso killer".^[59]

John Gill, a seven-year-old boy was found murdered in Manningham, Bradford, on 29 December 1888. His legs had been severed, his abdomen opened, his intestines drawn out, and his heart and one ear removed. The similarities with the murder of Mary Kelly led to press speculation that the Ripper had killed the boy.^[60] The boy's employer, milkman William Barrett, was twice arrested for the murder on circumstantial evidence but was released.^[60] No-one else was ever prosecuted.^[60]

Carrie Brown (nicknamed "Shakespeare", reportedly for quoting Shakespeare's sonnets) was strangled with clothing and then mutilated with a knife on 24 April 1891 in New York City.^[61] Her body was found with a large tear through her groin area and superficial cuts on her legs and back. No organs were removed from the scene, though an ovary, either purposely removed or unintentionally dislodged, was found upon the bed.^[61] At the time, the murder was compared to those in Whitechapel though the Metropolitan Police eventually ruled out any connection.^[61]

Investigation[link]

Inspector Frederick Abberline, 1888

The surviving police files on the Whitechapel murders allow a detailed view of investigative procedure in the Victorian era.^[62] A large team of policemen conducted house-to-house inquiries throughout Whitechapel. Forensic material was collected and examined. Suspects were identified, traced and either examined more closely or eliminated from the inquiry. Police work follows the same pattern today.^[62] Over 2000 people were interviewed, "upwards of 300" people were investigated, and 80 people were detained.^[63]

The investigation was initially conducted by the Metropolitan Police Whitechapel (H) Division Criminal Investigation Department (CID) headed by Detective Inspector Edmund Reid. After the murder of Nichols, Detective Inspectors Frederick Abberline, Henry Moore, and Walter Andrews were sent from Central Office at Scotland Yard to assist. After the Eddowes murder, which occurred within the City of London, the City Police under Detective Inspector James McWilliam were involved.^[8] However, overall direction of the murder enquiries was hampered by the fact that the newly appointed head of the CID, Robert Anderson, was on leave in Switzerland between 7 September and 6 October, during the time Chapman, Stride and Eddowes were killed.^[64] This prompted the Metropolitan Police Commissioner, Sir Charles Warren, to appoint Chief Inspector Donald Swanson to coordinate the enquiry from Scotland Yard.^[65]

"Blind-man's Buff": Punch cartoon by John Tenniel (22 September 1888) criticising the police's alleged incompetence. The failure of the police to capture the killer reinforced the attitude held by radicals that the police were inept and mismanaged.^[66]

Partly because of dissatisfaction with the police effort, a group of volunteer citizens in London's East End called the Whitechapel Vigilance Committee patrolled the streets looking for suspicious characters, petitioned the government to raise a reward for information about the killer, and hired private detectives to question witnesses independently.^[67]

Butchers, slaughterers, surgeons and physicians were suspected because of the manner of the mutilations. A surviving note from Major Henry Smith, Acting Commissioner of the City Police, indicates that the alibis of local butchers and slaughterers were investigated, with the result that they were eliminated from the inquiry.^[68] A report from Inspector Donald Swanson to the Home Office confirms that 76 butchers and slaughterers were visited, and that the inquiry encompassed all their employees for the previous six months.^[69] Some contemporary figures, including Queen Victoria, thought the pattern of the murders indicated that the culprit was a butcher or cattle drover on one of the cattle boats that plied between London and mainland Europe. Whitechapel was close to the London Docks,^[70] and usually such boats docked on Thursday or Friday and departed on Saturday or Sunday.^[71] The cattle boats were examined but the dates of the murders did not coincide with a single boat's movements and the transfer of a crewman between boats was also ruled out.^[72]