Violet-red Sentence Examples
violet-red
They are violet-red in colour, and on boiling or long standing with dilute acids they pass into the corresponding roseo-salts.
In this reaction urea is heated in a dry tube until it gives off ammonia freely; the residue is dissolved in water, made alkaline with caustic soda, and a drop of copper sulphate solution is added, when a fine violet-red coloration is produced.
It may be detected by the addition of an aqueous solution of potassium cyanide, with which it gives a violet-red coloration, due to the formation of isopurpuric acid.
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