Borden introduced its first nonfood consumer product, Casco Glue, in 1932. When the milk separates into curds and whey, pour off the liquid and wash it away. Add one-quarter cup of water and a tablespoon of baking soda. When the bubbling stops, you've got glue. Cheese is made from curds.
White glue is made from the casein of the curds.
While promoted by a spokesbull and made by a milk company, Elmer's Glue-All is a synthetic resin glue that does not contain casein. Before scientists discovered how to synthesize plastics from petroleum products, plants and animal fats were used to make natural plastics, which eventually decompose. Biodegradable plastic is made by adding starch to the plastic. Bacteria then feed on the buried plastic. In surgery, stitches are now made using plastics that slowly dissolve in body fluids.