- Louis Pasteur (1822-1895)
- Born in France.
- He developed the concept of immunochemistry.
- He initiated heat sterilization of milk.
- He observed optical isomers in tartaric acid.
- Theophile Jules Pelouze (1807-1867)
- Born in France.
- He isolated tannic acid.
- He discovered nitro-sulfates.
- He started the use of sodium sulfate in glass-making.
- Sir William Henry Perkin (1838-1907)
- Born in England.
- He synthesized the first organic dye and the first synthetic perfume.
- Joseph Priestley (1733-1804)
- Born in England.
- He discovered carbon monoxide, nitrous oxide, and oxygen.