Mineral Analysis With a Blowpipe

Oxides of calcium, barium, strontium, magnesium and aluminum are not reduced but they glow intensively under strong heating. 

In his translation of Cronstedts mineralogy von Engestrom had an appendix, Description of a mineralogical pocket laboratory and especially of the use of the blowpipe in mineralogy . 

According to von Engestrom, Cronstedt was a pioneer in using portable laboratories for mineral analysis in the field. Eigure 10.3 shows Torbern Bergman s portable laboratory with a silver blowpipe. 

It was also Gahn who introduced the method of melting a borax bead or a phosphate to form a dear bead in a loop of a platinum wire to study the color effects when a very small sample quantity is dissolved in the bead. Two examples  

Cobalt compounds give a blue color to the borax bead, whether hot or cold. 

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