Why Did A Doctor Inject Rabbits And A Dog With Bacteria After Autopsying A President?

Newly recovered documents shed light on an important and fascinating experiment after the death of the 25th American president.

Russell is a Science Writer with IFLScience and has a PhD in the History of Science, Medicine and Technology

Dr. Russell Moul

Russell is a Science Writer with IFLScience and has a PhD in the History of Science, Medicine and Technology.

Science Writer

Edited by Laura Simmons
Laura Simmons - Editor and Staff Writer

Laura Simmons

Editor and Staff Writer

Laura is an editor and staff writer at IFLScience. She obtained her Master's in Experimental Neuroscience from Imperial College London.

A photo looking down on a desk covered in the documents related to the archive of Dr Matzinger. The photo shows letters and pages open on the desk, along with a pencil, a letter knife, a smoking pipe and a top hat.

The archives of Dr Matzinger have now gone on sale for the first time, and they reveal insights into a strange set of experiments he performed following the death of President McKinley in 1901.

Image courtesy of The Raab Collection

A collection of previously unknown documents relating to a weird but important part of American history have gone to auction for the first time. The documents belonged to a physician who autopsied the body of US president William McKinley after his assassination in 1901. Following the autopsy, the doctor in question then performed a strange experiment involving rabbits and a pet dog, all in an attempt to figure out what killed the unfortunate president.

The archives of Dr Herman Matzinger, an influential expert on blood analysis at the time, have only recently emerged after they were rediscovered by his family. They have now been put up for auction at the Raab Collection for $80,000.


The documents include Matzinger’s laboratory notebook containing his scientific observations, a draft copy of his autopsy report, a copy of the final report, the government’s acknowledgement of the president’s death certificate, tickets to McKinley’s funeral, and other documents.

Through these sources, we gain important insights into what happened at the time of McKinley’s death as well as the doctor’s attempts to investigate the exact causes. So what happened?

Bullets, bodies, and pets 

On September 6, 1901, President William McKinley, the 25th American president, was attending the Pan-American Exposition in Buffalo, New York, when he was approached by an anarchist called Leon Czolgosz who went to shake his hand. In the process, Czolgosz shot McKinley in the chest at close range.

Soon after, McKinley was tended to by doctors who were able to stabilize him following an apparently successful operation. However, his health soon deteriorated, and he died on September 14. He was the third American president to be assassinated.

From the moment he died, rumours started to circulate about the exact cause of death. Although it was officially recorded as pancreatic necrosis, or necrotizing pancreatitis, there were those who suspected more.

Within the medical community, criticism fell on Dr Matthew Mann, the gynaecological surgeon who initially operated on McKinley.


Mann had been attending the Pan-American Exposition and was the first physician to respond. Mann had a hard time in his procedure, as he struggled to find the bullet in the layers of fat on McKinley’s body. In the end, he left the bullet in place and simply sewed up two stomach wounds that he found. It is possible this caused an infection that led to the president’s death.

In addition to a potential botched operation, there were those who believed Czolgosz had shot McKinley with a poisoned bullet, or one laced with bacteria. This conspiracy is still alive today.

In order to investigate these claims, Dr Matzinger was asked to perform a “bacteriological examination” of the president’s body, in addition to the autopsy. Through his work, he concluded that the infection had likely been caused by the bullets and not Mann’s operation, and that there was no evidence of poisoning.


The documents now on sale provide fascinating insights into how Matzinger reached these conclusions. In one test, the good doctor grew “whitish” bacteria cultures that he took from McKinley’s wound and then injected them into rabbits and a dog. We still have quite a few questions about this procedure – why he did it, who owned the animals and so on – but we do know that he carefully monitored the dog over the next few days. He noted the animal’s body temperature, which had become elevated, but ultimately the dog was “acting well”.

The documents also offer insights into the type of pressures that were on the doctor at the time. According to his letters, Matzinger was being pressed by Dr P.M. Rixey, who wanted the results ASAP. Still, Matzinger took his time and eventually submitted his report 18 days after McKinley’s death.

These documents really are a veritable treasure trove. They offer information that we rarely get to see in recorded history and tell us much about the context surrounding the president’s death, as well as how autopsies of high-ranking officials were performed.


  • tag
  • experiment,

  • death,

  • history,

  • autopsy,

  • assassination,

  • weird and wonderful,

  • weird history