Still the die is cast, and my trust is in my love of truth, and the candour of cultivated minds."(28) Then he goes on to say: (28) William Harvey: Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus, Francofurti, 1628, G.Moreton's facsimile reprint and translation, Canterbury, 1894, p.

48.
"I began to think whether there might not be A MOVEMENT, AS IT WERE, IN A CIRCLE.

Now this I afterwards found to be true; and I finally saw that the blood, forced by the action of the left ventricle into the arteries, was distributed to the body at large, and its several parts, in the same manner as it is sent through the lungs, impelled by the right ventricle into the pulmonary artery, and that it then passed through the veins and along the vena cava, and so round to the left ventricle in the manner already indicated."(29) (29) Ibid.p.

49.
The experiments dealing with the transmission of blood in the veins are very accurate, and he uses the old experiment that Fabricius had employed to show the valves, to demonstrate that the blood in the veins flows towards the heart.

For the first time a proper explanation of the action of the valves is given.