"Is it a surprise that into the vessel, in which the mercury has no inclination and no repugnance, not even the slightest, to being there, it should enter and should rise in a column high enough to make equilibrium with the weight of the external air which forces it up?"

This quote by Evangelista Torricelli is referring to the idea of atmospheric pressure. He is recommending that when a vessel is filled with mercury, the mercury will rise in the vessel until it reaches a level that amounts to the air pressure beyond the vessel. This is because the mercury has no preference or hostility to being in the vessel, so it will naturally rise till it is in equilibrium with the external air pressure. This idea is called Torricelli's Law, and it is used to determine atmospheric pressure. Torricelli's Law is an essential idea in physics and meteorology, as it assists us to comprehend the relationship between air pressure and the height of a column of liquid.