Casimir Davaine

Casimir Davaine ( born March 19, 1812 in Saint- Amand- les -Eaux, France, † October 14, 1882 in Garches, near Paris ) was a French physician. He that bacteria can provoke diseases in humans and animals showed the example of the first anthrax. During the trials he transferred the blood of infected sheep to smaller animals such as rabbits, rats or guinea pigs, which he established animal tests under laboratory conditions.

Life

Casimir Davaine was the sixth of nine children of a distiller. He went to Saint- Amand, Tournai and Lille to school and took in 1830 to study medicine in Paris. In 1835 he was "External " ( intern who is not resident in the hospital ) by Pierre Rayer at the Hôpital de la Charité, where he met the famous physiologist Claude Bernard, whose colleague, friend and family physician he was. In 1837 he graduated from medical school and settled as a practicing physician. He devoted his spare time to research in natural history and pathology.

In 1848 he was one of the founding members of the Société de Biologie. In 1858 he was awarded the Legion of Honor, 1868, he was given a seat in the Academy of Medicine. He bore the title of médecin par quartier of the French emperor, was therefore used for consultation on the health of the Emperor, without exclusively to serve as his personal physician. Davaine was one of the most famous physicians of his time. His patients included Marie Duplessis, who has become known as the " Lady of the Camellias ", Claude Bernard, his teacher Rayer and members of the Rothschild and d' Eichthal families.

In the Franco-German war of 1870/71 he served as a field doctor. During this time he wrote the book Les éléments du bonheur ( "Elements of Happiness" ), in which he spread his philosophy of life. He spent his last years in Garches, near Paris, where he grew roses after the war.

Work

Davaines work included work in bacteriology, parasitology, plant physiology, zoology, general biology and teratology. But Epochal were especially his work on anthrax, with whom he founded the medical and veterinary bacteriology.

Anthrax

As Davaine began to work on anthrax, it was known that the disease was contagious and virulent. 1823 Eloy Barthelemy had shown at the Veterinary School of Alfort, that he with the blood was transferred from the spleen of a diseased sheep on a healthy sheep anthrax. Nevertheless, the miasmatic theory of anthrax emergence was still predominant, after which disease should arise about miasms from the soil of irrigation or by other meteorological factors. Other authors made ​​bad food, dirty stables or " too much blood in the arteries " responsible.

In June and July 1850 Davaine accompanied his former teacher Rayer on a research trip in the Beauce region, near Chartres, where they transferred anthrax with the blood of diseased to healthy sheep. Observed under a microscope Rayer that in the blood of the artificially infected animals clumped red blood cells in the same manner as the output of animals. He also observed small thread-like corpuscles in the blood that were twice as long as a blood cell. This is the first observation of the anthrax pathogen Bacillus anthracis. However Rayer brought the " small, thread-like bodies " not with the disease in conjunction.

Published in 1855, the German physician Aloys Pollender a work for which he would have made 1849 observations already. He found in the blood " rod-shaped bodies " of which he speculated that they might belong to the bacteria. In this work, he asked if it constitutes the infectious agent to support this agent or to an irrelevant observation, but said that this question can not be answered. 1857/58 also observed another German researcher, Friedrich Brauell, the rod-shaped body, which had already seen Rayer and Pollender. It seemed to him as if the initially motionless fingers began to move later, so would vibrios. This confusion of anthrax with others occurring in the decay bacteria has long obstructed the progress of knowledge.

Davaine 1863 took his anthrax research again. He infected two rabbits and a white rat with the blood of a sheep that had died of anthrax. He was able to show that the blood of anthrax- infected animals was not infectious as long as the rod-shaped bodies were not published. For these bodies, he suggested the name before bactéridies. Further, he was able to demonstrate that rotten anthrax blood another disease triggered as anthrax during transmission, so Davaine differed from anthrax septicemia. Dried blood anthrax animals remained eleven months after he had dried it, virulent when he anfeuchtete it again and transferred. Birds and frogs proved in his attempts to be insensitive to anthrax. He also showed that not only the blood of the spleen - as had been believed until then - but the blood of any kind was infectious.

1864 examined Davaine the anthrax carbuncle ( malignant pustule ), ie, the localized form of skin anthrax in humans and found under the microscope, the same bacteria that he had seen in the blood of diseased animals. He confirmed the findings of Jean Fournier, who had shown in 1789 that anthrax can be transmitted from animals to humans.

Davaines results were attacked by Émile -Claude Leplat and Pierre -François Jaillard from the hospital Val -de- Grâce violently. They could not imagine that bacteria could excite a disease. In the eyes of Leplat and Jaillard the rod-shaped bodies were minor side effects. Davaine was finally able to show that a very different disease in the experiments to which Leplat and Jaillard appealed, - bovine septicemia - had been transferred. 1865 Davaine was honored by the Academy of Sciences of the Prix Bréant for his anthrax research, but there still remained room for doubt.

1868 Davaine tried to address these lingering doubts in a review article and reiterated that the " Bakteridien " were the causative agent of the disease. Above all, he pointed out that a particular plant disease was caused by bacteria. In this case, the bacteria cease to move when they were heated to at least 52 ° C, and then Davaine could not transmit the disease.

In the same year Davaine determined the incubation period of anthrax in guinea pigs. Death occurred 26-53 hours after the injection of blood anthrax animals one, depending on the dose Davaine had transferred. Davaine had thus shown that the incubation period of the dose was dependent and thus gained an additional argument for the causation of anthrax by the observed of him, " Bakteridien ".

In 1869 he succeeded in an elegant experiment: He diluted some blood from anthrax sick animals with distilled water, after 24 hours, the anthrax were sunk to the bottom of the vessel. When injected one drop from the bottom of the vessel in guinea pigs died when he took the other hand, a drop of the surface, they survived.

1873 showed Davaine that diluted blood anthrax animals lost its infectivity when it was heated for five minutes at 55 ° C. However, the blood was contagious when he dried it, even if it was then heated to 100 ° C. In addition, he examined various chemicals on their bactericidal effect.

However Davaine erred further in the transmission of the disease for which he was flying responsible. Also, he did not succeed in isolating the bacteria and grown in vitro. It was not until Robert Koch described the spore stage of the anthrax pathogen, and thus completed the life cycle of the bacterium. Louis Pasteur recognized on several occasions to the pacemaker role, the Casimir Davaine had played for him.