Note 4 — Chapter XII · HOW TO WORK.
Reading edition
Note.—Another way is to mix a little soil with rain water, stir it well, and put the litmus paper in it. Pure rain water is the only water that can be successfully used in this test.
Reading edition
Note.—Another way is to mix a little soil with rain water, stir it well, and put the litmus paper in it. Pure rain water is the only water that can be successfully used in this test.