Beer–Lambert law
Ley de Beer-Lambert
- Date
- 1729-1852 · confidence medium
- Place
- Bonn, North Rhine-Westphalia, Germany
- Credited to
- August Beer, building on earlier work by Pierre Bouguer (1729) and Johann Heinrich Lambert (1760)
- Field
- Communication
What was discovered
Bouguer observed in 1729, measuring stars from Paris, that light attenuates exponentially with distance travelled; Lambert formalized that relationship mathematically in 1760, and in 1852 Beer extended the principle to colored solutions, shaping the combined law relating light absorption to a substance's concentration. It is the basis of modern spectrophotometry.
This is a law with three authors over more than a century; it is dated to 1852, when Beer extended it to solutions and the current combined form was settled.
What it led to
- Modern spectrophotometry
- Quantitative chemical analysis by light absorption
Built on
- Bouguer's exponential attenuation observations (1729)
- Lambert's mathematical formalization (1760)