Sand vs soil, which will be the better filter? Soil is so important to what we eat and drink! It helps filter rainwater, chemicals, and waste into clean water. Farming also relies on healthy soil to ...

In many of the same hot regions of the world prone to drought and water contamination grows a tree whose seeds attract and kill bacteria in water. It's a thin-branched, gangly-looking plant ...

THE letter of Mr. C. J. Watson in NATURE for October 15, recommending that “Nachtblau” (night-blue) should be used for experiments on adsorption by sand, leads us to point out that so far back as 1999 ...