Scientists from DuPont wanted to find out if certain factory by-product were acids or bases. They tested dioxin dichlorobenzene, chloroaniline and water. They placed two tablespoons of each liquid in separate beakers. They took three strips of red Litmus paper and dipped one into each beaker then laid them out to dry. When they dried, they then recorded the color of the paper and whether it was an acid or a base. A positive base test is blue, a positive acid test is red, and in a neutral test, the paper does not change.