At the end of this time examine the test-paper to see if it has partly or altogether changed color.
When pure, both the salt and its solutions are neutral to test-paper, and are wholly volatilised by heat.
He dipped his test-paper into the vessel connected with the positive pole, and the water was still decidedly acid.
It is distinguished from meconia by its aqueous solution showing an alkaline reaction with test-paper.
The fluid is usually tasteless and without smell, and in reaction it is neutral to test-paper.
The resulting solution and jelly are also odourless, neutral to test-paper, free from unpleasant taste, and perfectly transparent.
It is neutral to test-paper, does not affect lime water, and is only slightly absorbed by pure water.
Pure ether should, however, be neutral to test-paper, although seldom so.
The presence of ozone is shown by the test-paper acquiring a purple tint when momentarily immersed in water.