Xilei LIN, Institut für Radiochemie, Technische Universität München, Garching, Germany
Problem Napoleon died on the island of St. Helena on 5 May 1821 at the age of 51. It was officially declared that his death was due to cancer of the stomach. This statement, however, was ques-tioned even at that time by Napoleon's household physicians.
Since then, extensive investigations have been conducted to clarify this issue.
In early 1960s, radiochemical neutron activation analysis (RNAA) made it possible for the first time to determine trace amounts of arsenic in hair. One of Napoleon's hairs was ana-lysed and a high arsenic content of 10.38 ppm was reported.
Accordingly it was suggested in 1961 that arsenic poisoning was the chief suspect in Napoleon's death. Later, two more of Napoleon's hairs, from another source, were analysed by RNAA. Uneven arsenic distribution along the length of the hairs was discovered. The growth rate of human hair is about 0.4 mm/d, so the arsenic distribution in the hair can be used to date arsenic intake. Since then, arsenic in more than 30 samples of Napoleon's hair has been analysed.
Nowadays a non-destructive method employing a ger-manium detector, instrumental neutron activation analysis (INAA), is used that is even more convenient. By INAA, it is possible to determine arsenic as well as other trace elements simultaneously in a single hair.
Why nuclear analytical techniques?
In this work an INAA procedure is applied to determine the contents of arsenic and mercury in two samples of Napoleon's hair. Three additional elements — chromium, antimony and zinc — are determined simultaneously and are reported as well. Mercury is a component of calomel, of which a great deal was consumed by Napoleon and which is considered to play an important role in the arsenic poisoning theory. Anti-mony is interesting because it was a component of many med-ications, particularly tartar emetic, which Napoleon
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frequently received during his last year. Chromium and zinc are essential elements.
How to solve the problem?
Two pieces of Napoleon’s hair, hereafter referred to as hair 1 and hair 2, were sent by post by R. Maury, a professor at the University of Montpellier, France, in a special parcel sealed by G. Kaendel, the Curator of the Museum of History in Lausanne, Switzerland. These two samples were taken from a strand of hair cut the day after Napoleon's death. The weights were 0.1722 and 0.2151 mg, respectively. The INAA results are presented in Table 1.
Arsenic and other trace elements in Napoleon’s hair
The arsenic contents found in this work are 1.85 ± 0.11 and 3.05 ± 0.18 ppm for the two hairs. These values are higher than the normal level nowadays.
The elevated content and non-uniform distribution of arsenic along Napoleon's hair are used as the main evidence to support the arsenic poisoning theory. The instigator for the murder was believed to be the Comte D'Artois, who was Louis XVIII's brother and later became Charles X. The Bourbon king wanted to be sure that Napoleon would not return to regain his throne. According to the arsenic poison-ing theory, Napoleon did not directly die of arsenic toxicosis.
Chronic arsenic poisoning was only the ‘prelude’, giving the public an impression that Napoleon was deteriorating in a normal and natural way from disease. According to the theory, his death was due to a lethal poisoning. Starting two months before his death, he frequently received tartar emetic (antimony potassium tartrate). The real purpose was to even-tually inhibit vomiting, so that the patient was no longer able to expel poisons. Then calomel and orgeat were given to relieve his constipation and great thirst. Constipation and thirst were symptoms of arsenic poisoning. Calomel is mercury chloride and orgeat is an orange flavoured drink which contains the oil of bitter almonds. This oil can be hydrolysed in the stomach to hydrocyanic acid. When calomel and orgeat are combined in the stomach, mercury cyanide is formed, which is said to have been ultimately responsible for Napoleon's death. For this reason the elements
mercury and antimony were determined in this work. The mercury content of 3.98 ± 0.29 ppm found in hair 2, however, is in the normal range of 0.5–10 ppm. However, the antimony contents in the two samples of Napoleon's hair, 4.47 ± 0.27 and 4.32 ± 0.38 ppm, as shown in Table 1, are much too high, regardless of whether they are compared with the reference concentration of 0.05–0.25 ppm or with the normal level of 0.016–1.3 ppm for the local population. The element antimony is not the only one found in Napoleon's hair in an unusual concentration. The concentrations of the two essential ele-ments chromium and zinc are also not normal. The normal level of the two elements nowadays is less than a few parts per million for chromium and between 150 and 250 ppm for zinc. The concentration of chromium found in Napoleon's hair is too high (10.5 ± 1.9 ppm), while the zinc content, 58 ± 13 ppm, is too low.
While no one seems to deny the elevated arsenic content in Napoleon's hair, the extensive investigations that have been carried out result in two diametrically opposed opinions. One adheres to the chronic arsenic poisoning theory mentioned above, and the other insists that Napoleon died of cancer. The latter theory can be supported by the following arguments.
The diagnosis of chronic arsenic poisoning should not be based on the elevated arsenic content in hair alone, but should include specific clinical features, which were not reported in TABLE 1. ELEMENT CONCENTRATIONS (ppm) OF ARSENIC, CHROMIUM, MERCURY, ANTIMONY AND ZINC IN SAMPLES OF NAPOLEON’S HAIR
Hair 1 Hair 2
Arsenic 1.85 ± 0.11 3.05 ± 0.18
Chromium 7.65a 10.5 ± 1.9
Mercury 1.84a 3.98 ± 0.29
Antimony 4.47 ± 0.27 4.32 ± 0.38
Zinc 35a 58 ± 13
a Information value.
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Napoleon's case. Regarding the elevated arsenic content, doubts exist whether the determined arsenic was really the endogenous/ingested one or was a result of contamination.
Hair absorbs externally applied arsenic on its outer surface and/or in the core, and it has been reported that it is not possi-ble to remove it completely by washing. Furthermore, because consumed arsenic is also deposited on the surface of the hair shaft and/or in the core, these two sources cannot be distin-guished by examining the hair. Moreover, external contami-nation can also be unevenly distributed along the hair shaft.
Attempts have been made to identify external contamination sources during the period of Napoleon's exile in St. Helena.
The possible contamination sources, including wallpaper, coal smoke, drinking water, cosmetics containing arsenic, and the arsenic compounds used as preservatives, were critically examined. Besides external contamination, the elevated arsenic content might also result from ingestion of arsenic as an impurity in tartar emetic. Owing to the similar chemistry of antimony and arsenic, the tartar emetic produced in the 19th century might have contained arsenic. All of these sources are possible, but so far it has not been possible to pos-itively determine what was responsible for the elevated arsenic content in Napoleon's hair.
The debate on the issue of who or what killed Napoleon will very likely continue. It is clear, however, that reliable ana-lytical data from neutron activation analysis will be helpful in the course of clarifying this historic mystery.