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Article by Aase R. Jacobsen and Lars Petersen - 2001
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How Tycho Brahe Really Died

Aase R. Jacobsen
Planetarium Curator
The Steno Museum
C. F. Møllers Allé bygn100
DK-8000 Århus C, Denmark

Lars Petersen
Planetarium Director
Orion Planetarium
Søvej 36 Jels
DK-6630 Rødding, Denmark.


This famous Danish astronomer died in Prague on the 24th of October 1601, eleven days after he had attended a banquet at the Bohemian count of Rosenberg. Tycho was too courteous to obey the calls of nature during the hour-long dinner and finally his bladder burst, which led to his death. Or so the story goes. But is this the real cause of Tychoºs death? Is it at all possible to die from a burst bladder? Or are there more likely explanations of his death?

Modern scientific investigations and analyses have given us new insight on the circumstances in those fateful days in Prague, October 1601. Three contemporary sources are available to diagnose Tychoºs last illness.

Johannes Kepler recounts in Tychoºs observation log that during the banquet with plenty of food and drink, Tycho Brahe didnºt want to empty his bladder and would wait until he got home; however he was unable to do so. After five sleepless nights he produced bloody urine, suffering great pain. Then followed more insomnia, fever and delirium. On the 24th October he passed away peacefully after hours of delirium exclaiming: ÑHave I not lived in vain!æ.

Tychoºs friend, the doctor Johann Jessenius Jessen, states in his funeral sermon: ÑThen followed urine retention (lacking ability to pass urine) and great pain, by which the blood was attracted causing cystitis with accompanying continuous fever. Of this came a slight delirium.æ

A note from the German doctor Johannes Wittich who visited Prague tells that Tycho died between 9 and 10 in the morning of the 24th October: ÑA stone made Tycho unable to urinate and he died from a burst bladder.æ

All three sources point to the fact that Tycho suffered prostatic hypertrophy (enlargement of the prostate gland) or another disorder of the urinary system followed by uremia. However, at that time it was known how to insert a catheter and relieve the pain that way and Tycho was rather young (54 years) to suffer from prostatic hypertrophy. Why wasnºt that done? Could there be other explanations of his death?

After Tycho Braheºs death, rumors arose that he had been victim of a poisoning case, and since the symptoms are in accordance with heavy metal poisoning and poisoning by certain plants this possibility must be taken seriously into consideration. The motive for poisoning could be both political and religious since neither the catholic council nor the nobility were pleased with the influence this protestant had gained on the weak emperor Rudolf II in Prague.

The first medical-legal investigation was made possible in 1991 when a small box (at a Danish flag ceremony on Tycho Braheºs grave in the Teyn Church in Prague) was handed over to the newly appointed Danish ambassador in the Czech Republic by the director of the Czech National Museum as a gift to the Danish government. The box contained a piece of shroud and some beard remnants. A small note explained that these items originated from the opening of Tychoºs grave in 1901 on the third centenary of his death, where the city authorities of Prague wanted to restore the sepulchral monument, and at the same time they investigated the rumour that Tychoºs corpse had been removed in 1620 when the Catholics took power in Bohemia. The grave was somewhat damaged and it contained a male corpse, very likely that of Tycho Brahe since part of the nose was missing, but no bladder stone was found! In addition, a female corpse was discovered, possibly that of Tychoºs wife Kristine Barbara, who outlived him by a few years.

When the beard remnants arrived in Denmark the director of the Ole Rømer Museum in Copenhagen, Claus Thykier, took the initiative for the itemºs transference to the Institute of Forensic Medicine at Copenhagen University for a possible clarification of the rumours of poisoning. The leader of the institute, Bent Kæmpe, consented to such an investigation, concentrating on arsenic, lead, and mercury by using an atomic absorption spectrometer.

Of the 4 cm long beard, 0.1233 gram were used for the analysis. By using this method on a single strand of hair or beard, it is not only possible to determine the concentration of a certain element but also the time since exposure to the poison. Hair (and beard) will grow at a certain rate, and by locating a high concentration of, for example, arsenic at a specific place on the hair, it can be calculated when the person was exposed to arsenic.

In Tycho Braheºs beard a relatively high amount of lead compared to the present population was found, so it can not be excluded that Tycho died from lead-poisoning. But more likely, the lead content could be caused by the historical fact that lead frequently was used in kitchen ware, water pipes and as a wine-sweetener. Also environmental influences such as lead in the coffin may have given a high concentration of lead in the beard.

The concentration of arsenic was not found to be high enough to have caused the death of Tycho Brahe.

However, the beard contained a much higher concentration of mercury than normal. Taken in consideration with the description of his illness, uremia, shortly before his death, this corresponds with symptoms of poisoning by mercury.

It is well known that Tycho, apart from being an astronomer, also had a great interest in chemistry and medicine, and he composed different medicines. Mercury is a well known ingredient in medicine in those days, and it is possible he composed medicines containing mercury and had taken such medicines shortly before his death.

Unfortunately, in this first forensic investigation, the beard from Tycho did not leave any trace of root remains. So it was not possible to determine how long a time before his death Tycho was exposed to mercury, nor if the mercury was taken over a short or longer period of time.

In 1996 it was possible to carry out another analysis using the PIXE-method (Particle Induced X-ray Emission) by J. Pallon at Fysiska Institutionen at Lund University, Sweden., this time on hair from Tycho with the root preserved. The result was that the mercury was not from an outside source but actually had been digested.

Using the growth rate of hair it was concluded that Tycho was poisoned by mercury one day before his death.

These forensic investigations show Tycho Brahe died of mercury poisoning. Even though it cannot be excluded, it is not likely that Tycho was murdered, but most likely he conducted his own death by using his own mercury-rich medicines the day before his death. This was done to help cure his disorder of the urinary system (prostatic hypertrophy or less likely bladder stones, since no stones were to be found in the coffin). It was not a burst bladder caused by his courteousness, but mercury in his own medicines that led to the uremia of which he died.

Adapted from:
Claus Thykier, Skalk 1994, vol. 1, p. 18
Claus Thykier, Skalk 2001, vol. 1, p. 12
Bent Kæmpe & Claus Thykier, Naturens Verden 1993, vol. 11-12, p. 425
Jan Tapdrup in Tycho Brahe, Skoletjenesten Øresund (Marianne Bomgren & Lotte Suhr ed.)

Reprinted from the Planetarian, Vol 30, #4, December 2001. Copyright 2001 International Planetarium Society. For permission to reproduce please contact Executive Editor, Sharon Shanks.

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