| http://www.w3.org/ns/prov#value | - Specific examples of temperature indicating materials used in the present invention include salts of metals such as cobalt, nickel, iron, copper, chromium and manganese, mixtures of two kinds of coloring matter different in hue, one of which sublimates at a specific temperature, mixtures of bismuth oxide and bismuth sulfide, materials the visual appreciation of which changes by melting, dispersion
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