Matthew franklin on Instagram: "This Porcelain Lid Insert Saved Thousands of Lives! This small piece of porcelain doesn’t look like much but it saved thousands of lives. What you’re seeing is an early porcelain jar lid insert, used in canning long before refrigeration existed. Back then, spoiled food and contamination were serious threats. Families depended on canning to survive. Early metal lids were often made from zinc or other alloys that could leach into food. This porcelain lid insert, pai