Now You Know (Source)
NOW I CAN BE A TRUE MERMAID
I actually did a report on this last year! The substance is called perfluorocarbon and because of its unique nature, it can hold enough oxygen inside of it for you to breathe it. You can breathe safely while inside it, but sometimes the transition from breathing in the perfluorocarbon and the air can be painful or uncomfortable as your lungs try to push the liquid out of them. In Dan Brown’s book The Lost Symbol, the process of reverting back to breathing the air can feel like being birthed.