“We live without inconvenience at the bottom of such a heavy atmospheric ocean, just as deep-sea fish do at the bottom of the sea. The external pressure, about 15 pounds per square inch, is balanced by the internal pressure of the gases contained in the pores of the flesh and liquids of our bodies. If we enter a highly rarefied air, the gases within our bodies expand, sometimes bursting blood vessels. Bleeding from the nose or lungs is a familiar occurrence at high altitudes where the air is very rare.”

Alfred Payson Gage (same source as above) wrote …

“When a quantity of gas is confined in a close vessel it exerts a pressure on all parts of the interior of the vessel. This pressure is out of all proportion to the weight of the gas, and in fact is not due to its weight. The pressure may exceed the weight a million times.”