Source A: Excerpt from a 19th-century medical journal

'The discovery of the specific bacteria causing tuberculosis by Koch marked a new era in microbiology, shifting medicine from theories of miasma to germ theory.' Provenance: Medical journal, 1882.

Historian View:

'Koch's work was driven by the need to find specific causes for diseases, moving away from outdated miasma theories and towards scientific microbiology.'

Source B: Excerpt from Koch's own writings

'The development of a reliable staining technique allowed us to see bacteria clearly, which was pivotal for identifying disease agents.' Provenance: Koch's publication, 1882.

Source C: Report from a 19th-century public health official

'Koch's discoveries led to the development of vaccines and improved sanitation practices, significantly reducing disease rates.' Provenance: Public health report, 1890.

Historian View:

'While Koch's discoveries revolutionized medicine, some critics argued that it took time for these advances to be widely adopted and that not all diseases could be explained by bacteria.'

Source D: Modern analysis

'Koch's work was crucial, but it was part of a broader scientific movement that transformed medicine over the following decades.' Provenance: Modern medical history review.