How did Jean Antoine Villemin show that tuberculosis could be transmitted between animals?

Jean Antoine Villemin demonstrated that tuberculosis is an infectious disease by conducting controlled inoculation experiments. Observing that soldiers in crowded barracks frequently contracted the illness, he hypothesized that it was transmissible rather than purely hereditary.

To test this, Villemin inoculated rabbits with tuberculous material taken from deceased human patients. Three months later, he discovered that the rabbits had developed tuberculous lesions. He further confirmed this transmission by successfully infecting rabbits using tuberculous material sourced from cows. Later in his research, he provided additional evidence by injecting animals with blood and sputum from human patients, proving that the disease could be spread through these biological materials.1