A simple test of acidity in a liquid using litmus, usually in the form of litmus paper.
A simple test of any attribute; a litmus test.
A dyestuff extracted from certain lichens, that changes color when exposed to pH levels greater than or less than certain critical levels.
paper containing a water-soluble pH indicator composed of a mixture of different dyes extracted from certain lichens. The resulting piece of paper is used to test materials for acidity, turning red when acidic and blue when alkaline.