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Nathan Burgess
Sean Rody
English 102
15 February 2016
The Science of Justice
The notorious British serial killer, Mary Ann Cotton, slowly murdered three of her husbands,
her children, her stepchildren, her mother, and neighbors who annoyed her. Much like other 18th and
19th century murderers, Mary Ann Cotton's weapon of choice was arsenic (Blum 80). This highly toxic
heavy metal came in the form of a white powder. It was colorless, odorless, and mostly flavorless,
making it the perfect poison to mix with food or drink. Victims of arsenic poisoning exhibit symptoms
that are often mistaken for disease or gastrointestinal distress (Tilstone 239). After several months, the
victim would die, seemingly of natural causes. Before the early 19th century, medical examiners had no
way to test for arsenic poisoning, allowing poisoners to easily get away with their crimes. The ease of
killing undetected was something Mary Ann Cotton relied on for years, allowing her to claim as many
as twenty victims with her deadly white powder (Bell 85). Unfortunately for Cotton, her murderous
ways ended at the gallows thanks to the development of forensic toxicology, the science of detecting
poisons used in homicide.
Toxicology was the first science founded specifically for forensic application, and therefore was
the first forensic science. The definition of forensic science is subject to some debate between
criminalists (forensic scientists). In the context of this paper, forensic science is defined as any
subsection of science that is used to investigate crimes. In addition to a disputed definition, the timeline
of forensic science is equally vague and debated. Dr. Suzanne Bell, head of the Bell Research Group
and the Forensic Science degree program at West Virginia University, writes “forensic science is a
derivative and exquisitely interdependent science that was not born but rather coalesced as a distinct
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profession in the 1800s. As such, there is no explicit timeline on which to drape a description of its
history” (Bell 14).
What event, if any, “coalesced” forensic science as a distinct profession? Forensic toxicology
was developed in response to the rampant use of arsenic in homicide. Many chemicals became widely
available to the European public, due to 18th century advancements in the field of chemistry. Arsenic
was a popular ingredient in many early 19th century products and could commonly be found in
wallpaper, dyes, candles, makeup, and was even prescribed as medicine (Hamlin). Mary Ann Cotton
was certainly not the first (nor the last) to employ arsenic as a murder weapon. In fact, the lethal use of
arsenic was so widespread, the French nicknamed it “poudre de succession,” or the inheritance powder
(Blum 1). Even if the circumstances behind a death aroused the suspicion of death investigators, the
lack of a reliable scientific method to detect unnatural levels of arsenic in a corpse made it nearly
impossible to prove that a poisoning had occurred.
Before toxicology, the only methods of arsenic detection were based on the senses and
observation. In one notable case, Mary Blandy, at the urging of her husband William Henry Cranston,
began mixing powders in her father's food that would supposedly lessen his ill-will towards William.
By the time she realized that the powder she was serving her father contained arsenic, it was too late.
Her father fell gravely ill in a matter of weeks and died soon after. During Mary's trial, a medical
examiner compared Mary's powder to arsenic powder and testified that they were the same. Other
doctors added to the circumstantial evidence by testifying that heating the powder yielded a garlicky
scent (results corresponding to arsenic) and commented that the organs of her father were unusually
well-preserved. Mary Blandy was found guilty and executed on April 6, 1752 (Bell 56-57).
Blandy's arrest and conviction was rare. Administered silently and privately, poisoning was still
almost impossible to detect. Evidence and testimony, as demonstrated with the Blandy case, was
largely circumstantial and subjective. Such evidence was the best medical examiners could muster until
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1818, when a young Spanish chemist by the name of Mateu Orfila set in motion events that lead to the
creation of the first purely scientific forensic science.
Orfila studied medicine at the Faculty of Medicine in Paris, France. After earning a doctorate,
Orfila remained in Paris and made a living giving chemistry lectures. During a demonstration on the
properties of arsenic, Orfila was surprised to see that arsenic reacted differently when mixed with
coffee (forming a grey-violet precipitate instead of white when mixed with lime) (Bertomeu-Sánchez).
Orfila began to experiment with dogs, giving them varying doses of heavy metal poisons, noting the
symptoms and postmortem signs of poisoning, In 1818, he compiled his research into a book entitled
Traité des poisons, the first work ever published on the science of toxicology .
Orfila's work inspired James Marsh, an English chemist, to develop a method for detecting
arsenic in organic tissue. The “Marsh test,” as it was later dubbed, involved dissolving suspected
arsenic-contaminated tissue in hydrochloric acid. Zinc shavings were then added to the solution and the
mixture heated. If arsenic was present in the solution, arsine gas would form. The arsine gas would
then be reheated, causing metallic arsenic to form a grey, mirror-like coating on the glassware (Bell
59). Through this process, Marsh had created the first scientific test for forensic use. In Marsh's paper
for the Society of Arts in London, he introduced the experiment by stating that he had found “improved
methods [for arsenic detection] in the food [and] contents of the stomach . . .” (Brindle). The Marsh test
was first successfully applied in court by Mateu Orfila himself during the trial of Marie LaFarge.
Marie LaFarge, an Englishwoman, had tired of her husband. Over the course of several months,
Marie served Charles LaFarge food tainted with arsenic until he succumbed to the toxins. During
Marie's trial, the Marsh test was employed by both the defense and the prosecution, but due to the test's
difficulty, high sensitivity, and the often arsenic-contaminated materials used in the test, the results
were attacked by both sides. Dissatisfied with the quality of the scientists performing the Marsh test on
Charles' remains, the prosecution sought the expertise of Orfila. Orfila, who had contributed much
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research to improving the Marsh test, took the stand to report his results, opening his testimony by
stating “I shall prove, first, that there is arsenic in the body of [Charles] LaFarge; second, that this
arsenic comes neither from the reagents with which we worked nor from the earth surrounding the
coffin; also, that the arsenic we found is not the arsenic component which is naturally found in every
human body” (Bell 62). His testimony resulted in a guilty verdict and life imprisonment for Marie
LaFarge. This was the first time the outcome of a trial had been decided solely on the basis of forensic
evidence.
Despite the success of the Marsh test, it was far from perfect. Due largely to the difficulty in
performing the test, it s use spread slowly. In 1841, Egar Hugo Reinsch created an alternative to the
Marsh test, one that was easier to perform. Pulitzer Prize-winning professor of science journalism at the
University of Wisconsin, Deborah Blum, explained that the Reinsch test was performed by dissolving a
tissue sample with potassium chlorate and hydrochloric acid. The liquid was then boiled to get rid of
the chlorine. The solution was then neutralized with ammonia and a strip of copper foil was soaked in
the solution for a few hours. After heating the copper strip, it would be inspected for a dark grey-purple
layer. This layer suggested the presence of a metal element. The strip was then washed and heated
again inside of a glass tube. A glaze would form on the glass and from that glaze scientists could
identify the poison. For instance, Blum states “mercury . . . glimmered silvery bright on the glass.
Arsenic formed a fine frost, glittering faintly with . . . octahedral crystals” (Blum 96). The Reinsch test
was notable for sending serial killer Mary Ann Cotton to her death (Bell 85).
With the revolutionary Marsh and Reinsch tests, forensic scientists were able to test and detect
heavy metal poisons. Unfortunately, this only covered half of the murderers' arsenal. Since both tests
only detected heavy metals, killers began to use plant-based poisons such as strychnine, nicotine,
hemlock and morphine (Bell 86). Once again, law enforcement was at a disadvantage. Blum quotes one
frustrated prosecutor during a morphine poisoning trial as crying, “henceforth let us tell would-be
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poisoners; do not use metallic poisons for they leave traces. Use plant poisons . . . Fear nothing; your
crime will go unpunished. There is no corpus delcti [physical evidence] for it cannot be found” (Blum
2).
The poisoners took notice. Lydie Fougnies, searching for a husband with wealth, married a man
by the name of Bocarme. To her disappointment, Bocarme was not the wealthy man as she had
believed him to be. Together the two hatched a plan based around a substantial inheritance from Lydie's
brother, Gustav Fougnies. Since Gustav was unmarried, all of his money, (a fortune inherited from his
father) would go to his sister. Lydie and Bocarme seemed to be in luck when Gustav had his leg
amputated and was close to death. The couple was waiting anxiously for Gustav to die when he proudly
made the announcement that he was getting married. Gustav only survived a few hours after his
announcement. Death investigators, highly suspicious of the circumstances of Gustav's death preserved
his organs and arrested Lydie and Bocarme (Bell 86).
Death investigators sought the expertise of Belgian chemist Jean Servais Stas. Stas had been
taught by the toxicological father himself, Orfila, and returned to Belgium to work as a chemistry
professor. After being contacted by the homicide investigators, Stas worked for months attempting to
create a method to deduce what plant-based, alkaloid poison killed Gustav. He performed alcoholic
extractions on samples of Gustav's organs until he extracted a large dose of nicotine, the highly
poisonous neurotoxin found in tobacco. After receiving Stas' findings, death investigators found
evidence that the murderous couple had extracted nicotine from a large amount of tobacco before the
night of Gustav's death. If this evidence wasn't damning enough, they also found the bodies of animals
that Lydie and Bocarme had used to test the effectiveness of their poison. Both Lydie and Bocarme
were convicted; Bocarme was executed (Bell 87).
Following Stas' success, toxicologists, now armed with the knowledge of how to extract poisons
from the tissues, set about finding ways to identify and improve the tests. Stas later improved his test
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with the help of a German chemist named Friedrich Otto. The improved test, named the Otto-Stas
method, increased both the number of alkaloids that could be extracted from organic tissue, as well as
the purity of the alkaloids.
The Marsh, the Reinsch and Stas-Otto tests are still used today, except they are now preliminary
tests. In other words, they are tests to determine whether it is likely (but not definite) or unlikely (but
not impossible) that a sample contains poison. More advanced and sensitive tests and then performed
before the evidence is admissible in court. Toxicology introduced forensic science as a counter to the
murderer's ultimate weapon. Orfila, Marsh, Reinsch, Otto, and Stas put the poisoners on the run; and
they're still running today.
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Works Cited
Bell, Suzanne. Crime and Circumstance: Investigating the History of Forensic Science. Westport:
Praeger, 2008. Print.
Bertomeu-Sánchez, José. "Popularizing Controversial Science: A Popular Treatise on Poisons by
Mateu Orfila (1818)." Medical History 53.3 (2009): 351-78. ProQuest Research Library.
Web. 5 Feb. 2012.
Blum, Deborah. The Poisoner's Handbook: Murder and the Birth of Forensic Medicine in Jazz Age
New York. New York: Penguin, 2010. Print.
Brindle, Ian D. "Vapour-Generation Analytical Chemistry: From Marsh to Multimode SampleIntroduction System." Analytical & Bioanalytical Chemistry 388.4 (2007): 735-41.
Academic Search Premier. Web. 5 Feb. 2012.
Hamlin, Christopher. "The Arsenic Century: How Victorian Britain Was Poisoned at Home, Work,
and Play." Medical History 55.2 (2011): 266-67. ProQuest Research Library. Web. 5 Feb.
2012.
Tilstone, William J., Kathleen A. Savage, and Leigh A. Clark. Forensic Science: An Encyclopedia
of History, Methods, and Techniques. Santa Barbara: ABC-CLIO, 2006. Print.