 Thus Boyle’s Law, for Boyle, was not a universal generalization about ideal gases: it was a strictly limited claim about common or atmospheric air. Boyle did add that “there is no cause to doubt, that if we had been here furnished with a greater quantity of quicksilver and a very strong tube, we might, by a further compression of the included air, have made it counter balance the pressure of a far taller and heavier cylinder of mercury.”