The Surprising Chemical Taxonomies of Minerals and Mollusks

In 1753, Carolus Linnaeus (1707-1778) published the Species Plantarum, providing the first systematic taxonomy of flowering plants and ferns. It was based largely on the external structures (morphologies) of flower parts. External appearance also played a major role in mineral classification. For example, gem- 

Now here s the tricky part. The flow of exhaled air onto the flame must be smooth and continuous, sometimes for minutes at a time. Try that. However, Bergman assures us that with practice the technique can be mastered—fill your cheeks with air and as you inhale and exhale through your nostrils, keep your cheeks replenished with air, and keep squeezing them steadily with the fingers of one hand so that the exhalation remains steady and continuous. Esteemed reader, you have my leave to take the day off and practice. 

There are several protocols to follow. First, expose the sample to the outer (fuel-deficient), oxidizing part of the flame. If the sample survives, expose it to 

FIGURE 171. Apparatus employed in blowpipe analysis of minerals was developed to a high state of technology in eighteenth-century Sweden (from Torbern Bergman s 1788 Physical and Chemical Essays). 

FIGURE 172. Chemical classification of minerals illustrated in Rene Haiiy, Traite de Mineralogie, Paris, 1801 (from the Othmer Library, CHF). 

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