In the formal language of economics, X and Y are substitutes if the demand for X increases when the price of Y increases, or a positive cross elasticity of demand.
Potting mix is the material that goes into a garden pot before you put seeds and plants into it. 1  It keeps the plant in place. 2  It holds water for the plantâs roots to soak up.  It contains nutrients that feed the plant.
Silly Putty is made from a mixture of silicone polymers (about 70 wt%) and other chemicals, including boric acid. Powdered fillers (clay and calcium carbonate) and dry pigments (to produce color or glitter) are also added.