Billy wanted to find out if certain liquids were acids or bases.  He used lemon juice, water, and glass cleaner for samples.  The water was used as the control.  He placed two tablespoons of each liquid into separate beakers. Then he took three strips of red Litmus paper and dipped one into each beaker then laid them out to dry. When they dried, he 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.