1. When Silver Spencer used glue on his bookmarks, it stuck and did not damage the pages.
2. Saccharine was discovered in 1879 by chemist Constantine Fahlberg while he worked in a university laboratory.
3. Alexander Fleming's discovery of mold and bacteria was when he left a Petri dish in his laboratory while on vacation and when he returned, he realized that there was a fungus on the dish, but no bacteria grew develop. He realized that there was a substance in that mushroom that was killing bacteria.
4. Chocolate cookies were born when Ruth Wakefield, owner of the Toll House Inn restaurant in the US, ran out of special chocolate for cookies so she decided to use regular chocolate instead. The chocolate did not mix well with the dough, so chocolate cookies were born.