Note 12 — HOME STUDIES IN CHEMISTRY AND PHYSICS.
Reading edition
“Torricellian Vacuum.” To produce this vacuum a small quantity of pure mercury is placed in the tube and boiled for some time. It is then allowed to cool and a further quantity, previously warmed, added, which is boiled, and so on until the tube is quite full; in this manner the moisture and the air which adhere to the sides of the tube pass off with the mercurial vapor.