- American Chemical Institute.1
- American Hygienic and Hydropathic Association of Physicians and Surgeons.1
- American Institute of Homeopathy.2
- American Medical Association.4
- American Medical Association. Committee on Adulterations and Sophistications of Drugs, Medicines, Chemicals, etc.1
- American Medical Association. Committee on Plans of Organization for State and County Medical Societies.1
- American Medical Association. Standing Committee on Medical Literature.1
- American Medical Society in Paris.3
- American Pharmaceutical Association.1
- American Provers' Union.1
- Ames, Joseph, 1816-18721
- Amussat, Alph. (Alphonse Auguste), 1821-18782
- Anderson, J. H.1
- Andrews, Edmund, 1824-19041
- Annan, Samuel, 1797-18681
- Anthony, John Gould, 1804-18771
- Antisell, Thomas, 1817-18931
- Antisell, Thomas, 1817-1893, author1
- Arink, G.1
- Armor, Samuel G. (Samuel Glasgow), 1819-18851