Before the era of spectrophotometers, chemists used color in their research. With their eyes and with equipment like this colorimeter, chemists could crudely identify substances and measure their concentration by comparing the color of a reference sample with that of an unknown. The method was simple but imprecise and subjective. With the eye as a “detector,” colorimetry relied on individual perceptions of hue, saturation, and brightness.
Listen to the latest episodes of CHF’s award-winning podcast.
Help us preserve and share the history of chemistry and related sciences. Make a tax-deductible tax-deductible gift online.
Celluloid Trading Card
©2010–2016 Chemical Heritage Foundation