© Science Museum / Science & Society Picture Library
Engraved diagram: 'When we desire to draw forth any pus we must apply the extreme orifice of the small tube [the needle],... to the part in which the matter is.' Pulling the inner plunger outwards produces a vacuum, and 'something else must enter to fill it, and as there is no other pasage but through the mouth of the small tube, we shall of necesity draw up through this any fluid that may be near. Again, when we wish to inject any liquid, we place it in the tube...and force down the liquid until we think the injection is effected.' Illustration from 'Gli artifitiosi et curiosi moti spiritali di Herrone' (commonly called 'Pneumatics') by Hero of Alexandria, published in Ferrara in 1589.